Gegeven een integer-array is het de taak om een integer-array in twee sub-arrays te verdelen om hun gemiddelden indien mogelijk gelijk te maken.
Voorbeelden:
Java-einde
Input : arr[] = {1 5 7 2 0}; Output : (0 1) and (2 4) Subarrays arr[0..1] and arr[2..4] have same average. Input : arr[] = {4 3 5 9 11}; Output : Not possible A Naïeve aanpak is om twee lussen uit te voeren en subarrays te vinden waarvan de gemiddelden gelijk zijn.
Uitvoering:
C++// Simple C++ program to find subarrays // whose averages are equal #include
// Simple Java program to find subarrays // whose averages are equal public class GFG { // Finding two subarrays // with equal average. static void findSubarrays(int[] arr int n) { boolean found = false; int lsum = 0; for (int i = 0; i < n - 1; i++) { lsum += arr[i]; int rsum = 0; for (int j = i + 1; j < n; j++) rsum += arr[j]; // If averages of arr[0...i] and // arr[i+1..n-1] are same. To avoid // floating point problems we compare // 'lsum*(n-i+1)' and 'rsum*(i+1)' // instead of 'lsum/(i+1)' and // 'rsum/(n-i+1)' if (lsum * (n - i - 1) == rsum * (i + 1)) { System.out.println('From (0 ' + i + ') to (' +(i + 1) + ' ' + (n - 1)+ ')'); found = true; } } // If no subarrays found if (found == false) System.out.println( 'Subarrays not ' + 'found'); } // Driver code static public void main (String[] args) { int[] arr = {1 5 7 2 0}; int n = arr.length; findSubarrays(arr n); } } // This code is contributed by Mukul Singh.
# Simple Python 3 program to find subarrays # whose averages are equal # Finding two subarrays with equal average. def findSubarrays(arr n): found = False lsum = 0 for i in range(n - 1): lsum += arr[i] rsum = 0 for j in range(i + 1 n): rsum += arr[j] # If averages of arr[0...i] and # arr[i+1..n-1] are same. To avoid # floating point problems we compare # 'lsum*(n-i+1)' and 'rsum*(i+1)' # instead of 'lsum/(i+1)' and # 'rsum/(n-i+1)' if (lsum * (n - i - 1) == rsum * (i + 1)): print('From' '(' 0 i ')' 'to' '(' i + 1 n - 1 ')') found = True # If no subarrays found if (found == False): print('Subarrays not found') # Driver code if __name__ == '__main__': arr = [1 5 7 2 0] n = len(arr) findSubarrays(arr n) # This code is contributed by ita_c
// Simple C# program to find subarrays // whose averages are equal using System; public class GFG { // Finding two subarrays // with equal average. static void findSubarrays(int []arr int n) { bool found = false; int lsum = 0; for (int i = 0; i < n - 1; i++) { lsum += arr[i]; int rsum = 0; for (int j = i + 1; j < n; j++) rsum += arr[j]; // If averages of arr[0...i] and // arr[i+1..n-1] are same. To avoid // floating point problems we compare // 'lsum*(n-i+1)' and 'rsum*(i+1)' // instead of 'lsum/(i+1)' and // 'rsum/(n-i+1)' if (lsum * (n - i - 1) == rsum * (i + 1)) { Console.WriteLine('From ( 0 ' + i + ') to(' + (i + 1) + ' ' + (n - 1) + ')'); found = true; } } // If no subarrays found if (found == false) Console.WriteLine( 'Subarrays not ' + 'found'); } // Driver code static public void Main () { int []arr = {1 5 7 2 0}; int n = arr.Length; findSubarrays(arr n); } } // This code is contributed by anuj_67.
// Simple PHP program to find subarrays // whose averages are equal // Finding two subarrays // with equal average. function findSubarrays( $arr $n) { $found = false; $lsum = 0; for ( $i = 0; $i < $n - 1; $i++) { $lsum += $arr[$i]; $rsum = 0; for ( $j = $i + 1; $j < $n; $j++) $rsum += $arr[$j]; // If averages of arr[0...i] and // arr[i+1..n-1] are same. To avoid // floating point problems we compare // 'lsum*(n-i+1)' and 'rsum*(i+1)' // instead of 'lsum/(i+1)' and 'rsum/(n-i+1)' if ($lsum * ($n - $i - 1) == $rsum * ($i + 1)) { echo 'From ( 0 ' $i' )'. ' to (' $i + 1' ' $n - 1')n'; $found = true; } } // If no subarrays found if ($found == false) echo 'Subarrays not found' ; } // Driver code $arr = array(1 5 7 2 0); $n = count($arr); findSubarrays($arr $n); // This code is contributed by vt_m ?> <script> // Simple Javascript program to find subarrays // whose averages are equal // Finding two subarrays // with equal average. function findSubarrays(arrn) { let found = false; let lsum = 0; for (let i = 0; i < n - 1; i++) { lsum += arr[i]; let rsum = 0; for (let j = i + 1; j < n; j++) rsum += arr[j]; // If averages of arr[0...i] and // arr[i+1..n-1] are same. To avoid // floating point problems we compare // 'lsum*(n-i+1)' and 'rsum*(i+1)' // instead of 'lsum/(i+1)' and // 'rsum/(n-i+1)' if (lsum * (n - i - 1) == rsum * (i + 1)) { document.write('From (0 ' + i + ') to (' +(i + 1) + ' ' + (n - 1)+ ')'); found = true; } } // If no subarrays found if (found == false) document.write( 'Subarrays not ' + 'found'); } // Driver code let arr=[1 5 7 2 0]; let n = arr.length; findSubarrays(arr n); // This code is contributed by avanitrachhadiya2155 </script>
Uitvoer
From (0 1) to (2 4)
Tijdcomplexiteit: O(n2)
Hulpruimte: O(1)
Een Efficiënte oplossing is om de som van array-elementen te vinden. Initialiseer Leftsum als nul. Voer een lus uit en vind Leftsum door elementen uit de array toe te voegen. Voor de rechtersom trekken we de bladeren af van de totale som, dan vinden we de rechtensom en vinden we het gemiddelde van de linker- en de rechtersom volgens hun index.
1) Compute sum of all array elements. Let this sum be 'sum' 2) Initialize leftsum = 0. 3) Run a loop for i=0 to n-1. a) leftsum = leftsum + arr[i] b) rightsum = sum - leftsum c) If average of left and right are same print current index as output.
Hieronder vindt u de implementatie van de bovenstaande aanpak:
C++// Efficient C++ program for // dividing array to make // average equal #include
// Efficient Java program for // dividing array to make // average equal import java.util.*; class GFG { static void findSubarrays(int arr[] int n) { // Find array sum int sum = 0; for (int i = 0; i < n; i++) sum += arr[i]; boolean found = false; int lsum = 0; for (int i = 0; i < n - 1; i++) { lsum += arr[i]; int rsum = sum - lsum; // If averages of arr[0...i] // and arr[i+1..n-1] are same. // To avoid floating point problems // we compare 'lsum*(n-i+1)' // and 'rsum*(i+1)' instead of // 'lsum/(i+1)' and 'rsum/(n-i+1)' if (lsum * (n - i - 1) == rsum * (i + 1)) { System.out.printf('From (%d %d) to (%d %d)n' 0 i i + 1 n - 1); found = true; } } // If no subarrays found if (found == false) System.out.println('Subarrays not found'); } // Driver code static public void main ( String []arg) { int arr[] = {1 5 7 2 0}; int n = arr.length; findSubarrays(arr n); } } // This code is contributed by Princi Singh
# Efficient Python program for # dividing array to make # average equal def findSubarrays(arr n): # Find array sum sum = 0; for i in range(n): sum += arr[i]; found = False; lsum = 0; for i in range(n - 1): lsum += arr[i]; rsum = sum - lsum; # If averages of arr[0...i] # and arr[i + 1..n - 1] are same. # To avoid floating point problems # we compare 'lsum*(n - i + 1)' # and 'rsum*(i + 1)' instead of # 'lsum / (i + 1)' and 'rsum/(n - i + 1)' if (lsum * (n - i - 1) == rsum * (i + 1)): print('From (%d %d) to (%d %d)n'% (0 i i + 1 n - 1)); found = True; # If no subarrays found if (found == False): print('Subarrays not found'); # Driver code if __name__ == '__main__': arr = [ 1 5 7 2 0 ]; n = len(arr); findSubarrays(arr n); # This code is contributed by Rajput-Ji
// Efficient C# program for // dividing array to make // average equal using System; class GFG { static void findSubarrays(int []arr int n) { // Find array sum int sum = 0; for (int i = 0; i < n; i++) sum += arr[i]; bool found = false; int lsum = 0; for (int i = 0; i < n - 1; i++) { lsum += arr[i]; int rsum = sum - lsum; // If averages of arr[0...i] // and arr[i+1..n-1] are same. // To avoid floating point problems // we compare 'lsum*(n-i+1)' // and 'rsum*(i+1)' instead of // 'lsum/(i+1)' and 'rsum/(n-i+1)' if (lsum * (n - i - 1) == rsum * (i + 1)) { Console.Write('From ({0} {1}) to ({2} {3})n' 0 i i + 1 n - 1); found = true; } } // If no subarrays found if (found == false) Console.WriteLine('Subarrays not found'); } // Driver code static public void Main ( String []arg) { int []arr = {1 5 7 2 0}; int n = arr.Length; findSubarrays(arr n); } } // This code is contributed by Rajput-Ji
<script> // Efficient Javascript program for // dividing array to make // average equal function findSubarrays(arrn) { // Find array sum let sum = 0; for (let i = 0; i < n; i++) sum += arr[i]; let found = false; let lsum = 0; for (let i = 0; i < n - 1; i++) { lsum += arr[i]; let rsum = sum - lsum; // If averages of arr[0...i] // and arr[i+1..n-1] are same. // To avoid floating point problems // we compare 'lsum*(n-i+1)' // and 'rsum*(i+1)' instead of // 'lsum/(i+1)' and 'rsum/(n-i+1)' if (lsum * (n - i - 1) == rsum * (i + 1)) { document.write( 'From (0 '+i+') to ('+(i+1)+' '+(n-1)+')n' ); found = true; } } // If no subarrays found if (found == false) document.write('Subarrays not found'); } // Driver code let arr=[1 5 7 2 0]; let n = arr.length; findSubarrays(arr n); // This code is contributed by rag2127 </script>
Uitvoer
From (0 1) to (2 4)
Tijdcomplexiteit: O(n)
Hulpruimte: O(1)
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