In dit onderwerp leren we over de willekeurige functie en hoe we het willekeurige getal kunnen genereren in de programmeertaal C. Zoals we weten, wordt de willekeurige functie gebruikt om het willekeurige getal tussen twee willekeurige getallen te vinden. In de programmeertaal C heeft de willekeurige functie twee ingebouwde functies: de functie rand() en srand(). Laten we deze functies in de C-taal begrijpen.
rand() functie
In de C-programmeertaal , is de functie rand() een bibliotheekfunctie die het willekeurige getal genereert in het bereik [0, RAND_MAX]. Wanneer we de functie rand() in een programma gebruiken, moeten we de stdlib.h header-bestand omdat de functie rand() is gedefinieerd in het stdlib-headerbestand. Er staat geen zaadnummer in. Daarom retourneert het dezelfde waarden als we hetzelfde programma keer op keer uitvoeren.
Opmerking: als de willekeurige getallen worden gegenereerd met de functie rand() zonder de functie srand() aan te roepen, retourneert deze telkens dezelfde reeks getallen als het programma wordt uitgevoerd.
Syntaxis
int rand (void)
De functie rand() retourneert de willekeurige gehele getallen waarvan het bereik loopt van 0 tot RAND_MAX. De RAND_MAX is een symbolische constante die wordt gedefinieerd in het headerbestand stdlib.h, waarvan de waarde groter maar kleiner is dan 32767, afhankelijk van de C-bibliotheken.
Genereer de willekeurige getallen met behulp van de functie rand().
Laten we een programma schrijven om het willekeurige getal te verkrijgen met behulp van de functie rand().
of
#include #include #include void main() { // use rand() function to generate the number printf (' The random number is: %d', rand()); printf ('
The random number is: %d', rand()); printf ('
The random number is: %d', rand()); printf ('
The random number is: %d', rand()); getch(); } Uitvoer
The random number is: 41 The random number is: 18467 The random number is: 6334 The random number is: 26500
Genereer 5 willekeurige getallen met de functie rand().
Laten we een programma bekijken dat 5 willekeurige getallen genereert met behulp van de functie rand() in de programmeertaal C.
willekeurig.c
#include #include int main() { int i; /* It returns the same sequence of random number on every execution of the program. */ printf(' Random Numbers are:
'); for (i = 0; i <5; i++) { printf(' %d', rand()); } return 0; < pre> <p> <strong>Output</strong> </p> <pre> Random Numbers are: 41 18467 6334 26500 19169 </pre> <p> <strong>2nd execution of the program:</strong> </p> <pre> Random Numbers are: 41 18467 6334 26500 19169 </pre> <p> <strong>3rd execution of the program</strong> </p> <pre> Random Numbers are: 41 18467 6334 26500 19169 </pre> <p>As we can see in the above output, it returns the same sequence of random numbers on every execution of the programming code.</p> <h3>Generate 10 random numbers from 1 to 100 using rand() function</h3> <p>Let's consider a program to find the random number in C using rand() function.</p> <p> <strong>rand_num.c</strong> </p> <pre> #include #include #include int main() { // declare the local variables int i, num; printf (' Program to get the random number from 1 to 100
'); for (i = 1; i <= 100 10; i++) { num="rand()" % + 1; use rand() function to get the random number printf (' %d ', num); getch(); } < pre> <p> <strong>Output</strong> </p> <pre> Program to get the random number from 1 to 100 42 68 35 1 70 25 79 59 63 65 </pre> <h2>srand() function</h2> <p>The srand() function is a C library function that determines the initial point to generate different series of pseudo-random numbers. A srand() function cannot be used without using a rand() function. The srand() function is required to set the value of the seed only once in a program to generate the different results of random integers before calling the rand() function.</p> <h3>Syntax</h3> <pre> int srand (unsigned int seed) </pre> <p> <strong>seed</strong> : It is an integer value that contains a seed for a new sequence of pseudo-random numbers.</p> <h3>Generate the random numbers using srand() function</h3> <p>Let's write a program to get the random numbers using srand() function in C.</p> <p> <strong>srandNum.c</strong> </p> <pre> #include #include #include // use time.h header file to use time int main() { int num, i; time_t t1; // declare time variable printf(' Enter a number to set the limit for a random number
'); scanf (' %d', &num); /* define the random number generator */ srand ( (unsigned) time (&t1)); // pass the srand() parameter printf('
'); // print the space /* generate random number between 0 to 50 */ for (i = 0; i <num; i++) { printf( '%d
', rand() % 50); } return 0; < pre> <p> <strong>Output</strong> </p> <pre> Enter a number to set the limit for a random number 10 44 32 23 35 6 33 1 4 22 18 </pre> <p> <strong>2nd execution of the program:</strong> </p> <pre> Enter a number to set the limit for a random number 15 13 30 24 27 4 30 28 35 36 13 44 39 21 5 7 </pre> <p>As we can see in the above Output, it returns different sequences of random numbers on every execution of the programming code.</p> <h3>Generate the random numbers using srand() and time() function</h3> <p>Let's write a program to get the random numbers using srand() with time() function.</p> <p> <strong>srand_time.c</strong> </p> <pre> #include #include int main() { int random = rand(); // assign the rand() function to random variable srand( time(0)); printf( ' Seed = %d', time(0)); printf( ' Random number = %d', random); return 0; } </pre> <p> <strong>Output</strong> </p> <pre> Seed = 1619450091 Random number = 41 </pre> <h3>Get a seeding value and print the random numbers using srand() function</h3> <p>Let's write a program to get the seed value and random numbers using srand() function.</p> <p> <strong>srand_time.c</strong> </p> <pre> #include #include int main() { int count; unsigned int seed; // use for randomize number printf(' Enter the Seeding value:
'); scanf(' %u', &seed); srand (seed); // pass parameter // generate random number between 1 to 6 for (count = 1; count <= 1 5="=" 10; ++count) { printf(' %5d', + (rand () % 6)); if (count 0) print the number in next line puts(' '); } return 0; < pre> <p> <strong>Output</strong> </p> <pre> Enter the Seeding value: 10 6 4 3 3 6 3 3 1 3 4 </pre> <p> <strong>2nd execution of the program:</strong> </p> <pre> Enter the Seeding value: 20 2 4 2 4 5 4 3 5 1 4 </pre> <p> <strong>3rd execution of the program:</strong> </p> <pre> Enter the Seeding value: 25 1 6 1 6 4 4 1 4 1 3 </pre> <p>As we can see in the above Output, when we executed the same program again and again with different seeds values, it displays the different sequences of a random number from 1 to 6.</p> <h3>Generate the random number using the random function</h3> <p>Let's create a program to use stadlib header file to get the random number using random function in C.</p> <p> <strong>func.c</strong> </p> <pre> #include #include #include int main() { int i, num, max, temp; printf (' Enter a number to set the limit of random numbers
'); scanf ('%d', num); printf (' Enter the maximum number from you want to get the random number:
'); scanf ('%d', max); printf (' %d random number from 0 to %d number are:
', num, max); randomize(); for (i = 1; i <= num; i++) { temp="random(max)" * use random() function to get the random number printf (' %d ', temp); print } getch(); < pre> <p> <strong>Output</strong> </p> <pre> Enter a number to set the limit of random numbers 17 Enter the maximum number from you want to get the random number: 100 15 random number from 0 to 100 number are: 42 68 35 1 70 25 79 59 63 28 75 89 90 43 7 4 65 </pre> <h2>Program to generate float random numbers</h2> <p>Let's consider a program to print the float random numbers in C.</p> <p> <strong>random1.c</strong> </p> <pre> #include #include #include int main() { srand( (unsigned int) time(NULL)); float f1 = 5.0; int i; printf(?Float random numbers are:
?); for (i = 0; i<10; i++) { printf('%f', ((float) rand() rand_max) * f1); printf('
'); } return 0; < pre> <p> <strong>Output</strong> </p> <pre> Float random numbers are: 1.208075 1.658376 4.645070 2.298807 3.117161 0.961486 4.115573 4.336223 2.894833 2.249825 </pre> <hr></10;></pre></=></pre></=></pre></num;></pre></=></pre></5;> 2e uitvoering van het programma:
Random Numbers are: 41 18467 6334 26500 19169
3e uitvoering van het programma
Random Numbers are: 41 18467 6334 26500 19169
Zoals we in de bovenstaande uitvoer kunnen zien, retourneert het dezelfde reeks willekeurige getallen bij elke uitvoering van de programmeercode.
Genereer 10 willekeurige getallen van 1 tot 100 met behulp van de functie rand().
Laten we een programma overwegen om het willekeurige getal in C te vinden met behulp van de functie rand().
rand_num.c
#include #include #include int main() { // declare the local variables int i, num; printf (' Program to get the random number from 1 to 100
'); for (i = 1; i <= 100 10; i++) { num="rand()" % + 1; use rand() function to get the random number printf (\' %d \', num); getch(); } < pre> <p> <strong>Output</strong> </p> <pre> Program to get the random number from 1 to 100 42 68 35 1 70 25 79 59 63 65 </pre> <h2>srand() function</h2> <p>The srand() function is a C library function that determines the initial point to generate different series of pseudo-random numbers. A srand() function cannot be used without using a rand() function. The srand() function is required to set the value of the seed only once in a program to generate the different results of random integers before calling the rand() function.</p> <h3>Syntax</h3> <pre> int srand (unsigned int seed) </pre> <p> <strong>seed</strong> : It is an integer value that contains a seed for a new sequence of pseudo-random numbers.</p> <h3>Generate the random numbers using srand() function</h3> <p>Let's write a program to get the random numbers using srand() function in C.</p> <p> <strong>srandNum.c</strong> </p> <pre> #include #include #include // use time.h header file to use time int main() { int num, i; time_t t1; // declare time variable printf(' Enter a number to set the limit for a random number
'); scanf (' %d', &num); /* define the random number generator */ srand ( (unsigned) time (&t1)); // pass the srand() parameter printf('
'); // print the space /* generate random number between 0 to 50 */ for (i = 0; i <num; i++) { printf( \'%d
\', rand() % 50); } return 0; < pre> <p> <strong>Output</strong> </p> <pre> Enter a number to set the limit for a random number 10 44 32 23 35 6 33 1 4 22 18 </pre> <p> <strong>2nd execution of the program:</strong> </p> <pre> Enter a number to set the limit for a random number 15 13 30 24 27 4 30 28 35 36 13 44 39 21 5 7 </pre> <p>As we can see in the above Output, it returns different sequences of random numbers on every execution of the programming code.</p> <h3>Generate the random numbers using srand() and time() function</h3> <p>Let's write a program to get the random numbers using srand() with time() function.</p> <p> <strong>srand_time.c</strong> </p> <pre> #include #include int main() { int random = rand(); // assign the rand() function to random variable srand( time(0)); printf( ' Seed = %d', time(0)); printf( ' Random number = %d', random); return 0; } </pre> <p> <strong>Output</strong> </p> <pre> Seed = 1619450091 Random number = 41 </pre> <h3>Get a seeding value and print the random numbers using srand() function</h3> <p>Let's write a program to get the seed value and random numbers using srand() function.</p> <p> <strong>srand_time.c</strong> </p> <pre> #include #include int main() { int count; unsigned int seed; // use for randomize number printf(' Enter the Seeding value:
'); scanf(' %u', &seed); srand (seed); // pass parameter // generate random number between 1 to 6 for (count = 1; count <= 1 5="=" 10; ++count) { printf(\' %5d\', + (rand () % 6)); if (count 0) print the number in next line puts(\' \'); } return 0; < pre> <p> <strong>Output</strong> </p> <pre> Enter the Seeding value: 10 6 4 3 3 6 3 3 1 3 4 </pre> <p> <strong>2nd execution of the program:</strong> </p> <pre> Enter the Seeding value: 20 2 4 2 4 5 4 3 5 1 4 </pre> <p> <strong>3rd execution of the program:</strong> </p> <pre> Enter the Seeding value: 25 1 6 1 6 4 4 1 4 1 3 </pre> <p>As we can see in the above Output, when we executed the same program again and again with different seeds values, it displays the different sequences of a random number from 1 to 6.</p> <h3>Generate the random number using the random function</h3> <p>Let's create a program to use stadlib header file to get the random number using random function in C.</p> <p> <strong>func.c</strong> </p> <pre> #include #include #include int main() { int i, num, max, temp; printf (' Enter a number to set the limit of random numbers
'); scanf ('%d', num); printf (' Enter the maximum number from you want to get the random number:
'); scanf ('%d', max); printf (' %d random number from 0 to %d number are:
', num, max); randomize(); for (i = 1; i <= num; i++) { temp="random(max)" * use random() function to get the random number printf (\' %d \', temp); print } getch(); < pre> <p> <strong>Output</strong> </p> <pre> Enter a number to set the limit of random numbers 17 Enter the maximum number from you want to get the random number: 100 15 random number from 0 to 100 number are: 42 68 35 1 70 25 79 59 63 28 75 89 90 43 7 4 65 </pre> <h2>Program to generate float random numbers</h2> <p>Let's consider a program to print the float random numbers in C.</p> <p> <strong>random1.c</strong> </p> <pre> #include #include #include int main() { srand( (unsigned int) time(NULL)); float f1 = 5.0; int i; printf(?Float random numbers are:
?); for (i = 0; i<10; i++) { printf(\'%f\', ((float) rand() rand_max) * f1); printf(\'
\'); } return 0; < pre> <p> <strong>Output</strong> </p> <pre> Float random numbers are: 1.208075 1.658376 4.645070 2.298807 3.117161 0.961486 4.115573 4.336223 2.894833 2.249825 </pre> <hr></10;></pre></=></pre></=></pre></num;></pre></=> strand() functie
De functie srand() is een C-bibliotheekfunctie die het beginpunt bepaalt voor het genereren van verschillende reeksen pseudo-willekeurige getallen. Een functie srand() kan niet worden gebruikt zonder een functie rand() te gebruiken. De functie srand() is vereist om de waarde van het zaad slechts één keer in een programma in te stellen om de verschillende resultaten van willekeurige gehele getallen te genereren voordat de functie rand() wordt aangeroepen.
Syntaxis
int srand (unsigned int seed)
zaad : Het is een geheel getal dat een kiem bevat voor een nieuwe reeks pseudo-willekeurige getallen.
Genereer de willekeurige getallen met behulp van de functie srand().
Laten we een programma schrijven om de willekeurige getallen te verkrijgen met behulp van de functie srand() in C.
strandNum.c
#include #include #include // use time.h header file to use time int main() { int num, i; time_t t1; // declare time variable printf(' Enter a number to set the limit for a random number
'); scanf (' %d', &num); /* define the random number generator */ srand ( (unsigned) time (&t1)); // pass the srand() parameter printf('
'); // print the space /* generate random number between 0 to 50 */ for (i = 0; i <num; i++) { printf( \'%d
\', rand() % 50); } return 0; < pre> <p> <strong>Output</strong> </p> <pre> Enter a number to set the limit for a random number 10 44 32 23 35 6 33 1 4 22 18 </pre> <p> <strong>2nd execution of the program:</strong> </p> <pre> Enter a number to set the limit for a random number 15 13 30 24 27 4 30 28 35 36 13 44 39 21 5 7 </pre> <p>As we can see in the above Output, it returns different sequences of random numbers on every execution of the programming code.</p> <h3>Generate the random numbers using srand() and time() function</h3> <p>Let's write a program to get the random numbers using srand() with time() function.</p> <p> <strong>srand_time.c</strong> </p> <pre> #include #include int main() { int random = rand(); // assign the rand() function to random variable srand( time(0)); printf( ' Seed = %d', time(0)); printf( ' Random number = %d', random); return 0; } </pre> <p> <strong>Output</strong> </p> <pre> Seed = 1619450091 Random number = 41 </pre> <h3>Get a seeding value and print the random numbers using srand() function</h3> <p>Let's write a program to get the seed value and random numbers using srand() function.</p> <p> <strong>srand_time.c</strong> </p> <pre> #include #include int main() { int count; unsigned int seed; // use for randomize number printf(' Enter the Seeding value:
'); scanf(' %u', &seed); srand (seed); // pass parameter // generate random number between 1 to 6 for (count = 1; count <= 1 5="=" 10; ++count) { printf(\' %5d\', + (rand () % 6)); if (count 0) print the number in next line puts(\' \'); } return 0; < pre> <p> <strong>Output</strong> </p> <pre> Enter the Seeding value: 10 6 4 3 3 6 3 3 1 3 4 </pre> <p> <strong>2nd execution of the program:</strong> </p> <pre> Enter the Seeding value: 20 2 4 2 4 5 4 3 5 1 4 </pre> <p> <strong>3rd execution of the program:</strong> </p> <pre> Enter the Seeding value: 25 1 6 1 6 4 4 1 4 1 3 </pre> <p>As we can see in the above Output, when we executed the same program again and again with different seeds values, it displays the different sequences of a random number from 1 to 6.</p> <h3>Generate the random number using the random function</h3> <p>Let's create a program to use stadlib header file to get the random number using random function in C.</p> <p> <strong>func.c</strong> </p> <pre> #include #include #include int main() { int i, num, max, temp; printf (' Enter a number to set the limit of random numbers
'); scanf ('%d', num); printf (' Enter the maximum number from you want to get the random number:
'); scanf ('%d', max); printf (' %d random number from 0 to %d number are:
', num, max); randomize(); for (i = 1; i <= num; i++) { temp="random(max)" * use random() function to get the random number printf (\' %d \', temp); print } getch(); < pre> <p> <strong>Output</strong> </p> <pre> Enter a number to set the limit of random numbers 17 Enter the maximum number from you want to get the random number: 100 15 random number from 0 to 100 number are: 42 68 35 1 70 25 79 59 63 28 75 89 90 43 7 4 65 </pre> <h2>Program to generate float random numbers</h2> <p>Let's consider a program to print the float random numbers in C.</p> <p> <strong>random1.c</strong> </p> <pre> #include #include #include int main() { srand( (unsigned int) time(NULL)); float f1 = 5.0; int i; printf(?Float random numbers are:
?); for (i = 0; i<10; i++) { printf(\'%f\', ((float) rand() rand_max) * f1); printf(\'
\'); } return 0; < pre> <p> <strong>Output</strong> </p> <pre> Float random numbers are: 1.208075 1.658376 4.645070 2.298807 3.117161 0.961486 4.115573 4.336223 2.894833 2.249825 </pre> <hr></10;></pre></=></pre></=></pre></num;> 2e uitvoering van het programma:
Enter a number to set the limit for a random number 15 13 30 24 27 4 30 28 35 36 13 44 39 21 5 7
Zoals we in de bovenstaande uitvoer kunnen zien, retourneert het verschillende reeksen willekeurige getallen bij elke uitvoering van de programmeercode.
Genereer de willekeurige getallen met behulp van de functies srand() en time().
Laten we een programma schrijven om de willekeurige getallen te verkrijgen met behulp van srand() met de functie time().
strand_tijd.c
#include #include int main() { int random = rand(); // assign the rand() function to random variable srand( time(0)); printf( ' Seed = %d', time(0)); printf( ' Random number = %d', random); return 0; } Uitvoer
pvr volledige vorm
Seed = 1619450091 Random number = 41
Haal een Seeding-waarde op en druk de willekeurige getallen af met de functie srand().
Laten we een programma schrijven om de startwaarde en willekeurige getallen te verkrijgen met behulp van de functie srand().
strand_tijd.c
#include #include int main() { int count; unsigned int seed; // use for randomize number printf(' Enter the Seeding value:
'); scanf(' %u', &seed); srand (seed); // pass parameter // generate random number between 1 to 6 for (count = 1; count <= 1 5="=" 10; ++count) { printf(\' %5d\', + (rand () % 6)); if (count 0) print the number in next line puts(\' \'); } return 0; < pre> <p> <strong>Output</strong> </p> <pre> Enter the Seeding value: 10 6 4 3 3 6 3 3 1 3 4 </pre> <p> <strong>2nd execution of the program:</strong> </p> <pre> Enter the Seeding value: 20 2 4 2 4 5 4 3 5 1 4 </pre> <p> <strong>3rd execution of the program:</strong> </p> <pre> Enter the Seeding value: 25 1 6 1 6 4 4 1 4 1 3 </pre> <p>As we can see in the above Output, when we executed the same program again and again with different seeds values, it displays the different sequences of a random number from 1 to 6.</p> <h3>Generate the random number using the random function</h3> <p>Let's create a program to use stadlib header file to get the random number using random function in C.</p> <p> <strong>func.c</strong> </p> <pre> #include #include #include int main() { int i, num, max, temp; printf (' Enter a number to set the limit of random numbers
'); scanf ('%d', num); printf (' Enter the maximum number from you want to get the random number:
'); scanf ('%d', max); printf (' %d random number from 0 to %d number are:
', num, max); randomize(); for (i = 1; i <= num; i++) { temp="random(max)" * use random() function to get the random number printf (\' %d \', temp); print } getch(); < pre> <p> <strong>Output</strong> </p> <pre> Enter a number to set the limit of random numbers 17 Enter the maximum number from you want to get the random number: 100 15 random number from 0 to 100 number are: 42 68 35 1 70 25 79 59 63 28 75 89 90 43 7 4 65 </pre> <h2>Program to generate float random numbers</h2> <p>Let's consider a program to print the float random numbers in C.</p> <p> <strong>random1.c</strong> </p> <pre> #include #include #include int main() { srand( (unsigned int) time(NULL)); float f1 = 5.0; int i; printf(?Float random numbers are:
?); for (i = 0; i<10; i++) { printf(\'%f\', ((float) rand() rand_max) * f1); printf(\'
\'); } return 0; < pre> <p> <strong>Output</strong> </p> <pre> Float random numbers are: 1.208075 1.658376 4.645070 2.298807 3.117161 0.961486 4.115573 4.336223 2.894833 2.249825 </pre> <hr></10;></pre></=></pre></=> 2e uitvoering van het programma:
Enter the Seeding value: 20 2 4 2 4 5 4 3 5 1 4
3e uitvoering van het programma:
Enter the Seeding value: 25 1 6 1 6 4 4 1 4 1 3
Zoals we in de bovenstaande uitvoer kunnen zien, worden, wanneer we hetzelfde programma keer op keer met verschillende Seed-waarden uitvoeren, de verschillende reeksen van een willekeurig getal van 1 tot 6 weergegeven.
Genereer het willekeurige getal met behulp van de willekeurige functie
Laten we een programma maken om het stadlib-headerbestand te gebruiken om het willekeurige getal te verkrijgen met behulp van de willekeurige functie in C.
func.c
#include #include #include int main() { int i, num, max, temp; printf (' Enter a number to set the limit of random numbers
'); scanf ('%d', num); printf (' Enter the maximum number from you want to get the random number:
'); scanf ('%d', max); printf (' %d random number from 0 to %d number are:
', num, max); randomize(); for (i = 1; i <= num; i++) { temp="random(max)" * use random() function to get the random number printf (\' %d \', temp); print } getch(); < pre> <p> <strong>Output</strong> </p> <pre> Enter a number to set the limit of random numbers 17 Enter the maximum number from you want to get the random number: 100 15 random number from 0 to 100 number are: 42 68 35 1 70 25 79 59 63 28 75 89 90 43 7 4 65 </pre> <h2>Program to generate float random numbers</h2> <p>Let's consider a program to print the float random numbers in C.</p> <p> <strong>random1.c</strong> </p> <pre> #include #include #include int main() { srand( (unsigned int) time(NULL)); float f1 = 5.0; int i; printf(?Float random numbers are:
?); for (i = 0; i<10; i++) { printf(\'%f\', ((float) rand() rand_max) * f1); printf(\'
\'); } return 0; < pre> <p> <strong>Output</strong> </p> <pre> Float random numbers are: 1.208075 1.658376 4.645070 2.298807 3.117161 0.961486 4.115573 4.336223 2.894833 2.249825 </pre> <hr></10;></pre></=> Programma om zwevende willekeurige getallen te genereren
Laten we een programma overwegen dat de willekeurige zwevende getallen in C afdrukt.
willekeurig1.c
#include #include #include int main() { srand( (unsigned int) time(NULL)); float f1 = 5.0; int i; printf(?Float random numbers are:
?); for (i = 0; i<10; i++) { printf(\\'%f\\', ((float) rand() rand_max) * f1); printf(\\'
\\'); } return 0; < pre> <p> <strong>Output</strong> </p> <pre> Float random numbers are: 1.208075 1.658376 4.645070 2.298807 3.117161 0.961486 4.115573 4.336223 2.894833 2.249825 </pre> <hr></10;>