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Tel alle gesorteerde rijen in een matrix

Gegeven een matrix van m*n-grootte is het de taak om alle rijen in een matrix te tellen die in strikt oplopende volgorde of in strikt afnemende volgorde zijn gesorteerd?

Voorbeelden:  

Input : m = 4 n = 5  
mat[m][n] = 1 2 3 4 5
4 3 1 2 6
8 7 6 5 4
5 7 8 9 10
Output: 3

Het idee is eenvoudig en omvat twee doorgangen van de matrix. 



  1. Beweeg vanaf de linkerkant van de matrix om alle rijen te tellen die zich in de matrix bevinden strikt toenemende orde  
  2. Beweeg vanaf de rechterkant van de matrix om alle rijen te tellen die zich in de matrix bevinden strikt afnemende volgorde

Hieronder ziet u de implementatie van bovenstaand idee. 

C++
// C++ program to find number of sorted rows #include    #define MAX 100 using namespace std; // Function to count all sorted rows in a matrix int sortedCount(int mat[][MAX] int r int c) {  int result = 0; // Initialize result  // Start from left side of matrix to  // count increasing order rows  for (int i=0; i<r; i++)  {  // Check if there is any pair of element  // that are not in increasing order.  int j;  for (j=0; j<c-1; j++)  if (mat[i][j+1] <= mat[i][j])  break;  // If the loop didn't break (All elements  // of current row were in increasing order)  if (j == c-1)  result++;  }  // Start from right side of matrix to  // count increasing order rows ( reference  // to left these are in decreasing order )  for (int i=0; i<r; i++)  {  // Check if there is any pair of element  // that are not in decreasing order.  int j;  for (j=c-1; j>0; j--)  if (mat[i][j-1] <= mat[i][j])  break;  // Note c > 1 condition is required to make  // sure that a single column row is not counted  // twice (Note that a single column row is sorted  // both in increasing and decreasing order)   if (c > 1 && j == 0)  result++;  }  return result; } // Driver program to run the case int main() {  int m = 4 n = 5;  int mat[][MAX] = {{1 2 3 4 5}  {4 3 1 2 6}  {8 7 6 5 4}  {5 7 8 9 10}};  cout << sortedCount(mat m n);  return 0; } 
Java
// Java program to find number of sorted rows class GFG {    static int MAX = 100;  // Function to count all sorted rows in a matrix  static int sortedCount(int mat[][] int r int c)  {  int result = 0; // Initialize result  // Start from left side of matrix to  // count increasing order rows  for (int i = 0; i < r; i++) {    // Check if there is any pair of element  // that are not in increasing order.  int j;  for (j = 0; j < c - 1; j++)  if (mat[i][j + 1] <= mat[i][j])  break;  // If the loop didn't break (All elements  // of current row were in increasing order)  if (j == c - 1)  result++;  }  // Start from right side of matrix to  // count increasing order rows ( reference  // to left these are in decreasing order )  for (int i = 0; i < r; i++) {    // Check if there is any pair of element  // that are not in decreasing order.  int j;  for (j = c - 1; j > 0; j--)  if (mat[i][j - 1] <= mat[i][j])  break;  // Note c > 1 condition is required to make  // sure that a single column row is not counted  // twice (Note that a single column row is sorted  // both in increasing and decreasing order)  if (c > 1 && j == 0)  result++;  }  return result;  }    // Driver code  public static void main(String arg[])  {  int m = 4 n = 5;  int mat[][] = { { 1 2 3 4 5 }  { 4 3 1 2 6 }  { 8 7 6 5 4 }  { 5 7 8 9 10 } };  System.out.print(sortedCount(mat m n));  } } // This code is contributed by Anant Agarwal. 
Python
# Python3 program to find number  # of sorted rows def sortedCount(mat r c): result = 0 # Start from left side of matrix to  # count increasing order rows  for i in range(r): # Check if there is any pair of element  # that are not in increasing order. j = 0 for j in range(c - 1): if mat[i][j + 1] <= mat[i][j]: break # If the loop didn't break (All elements  # of current row were in increasing order) if j == c - 2: result += 1 # Start from right side of matrix to  # count increasing order rows ( reference  # to left these are in decreasing order ) for i in range(0 r): # Check if there is any pair of element  # that are not in decreasing order. j = 0 for j in range(c - 1 0 -1): if mat[i][j - 1] <= mat[i][j]: break # Note c > 1 condition is required to  # make sure that a single column row  # is not counted twice (Note that a  # single column row is sorted both  # in increasing and decreasing order) if c > 1 and j == 1: result += 1 return result # Driver code m n = 4 5 mat = [[1 2 3 4 5] [4 3 1 2 6] [8 7 6 5 4] [5 7 8 9 10]] print(sortedCount(mat m n)) # This code is contributed by # Mohit kumar 29 (IIIT gwalior) 
C#
// C# program to find number of sorted rows using System; class GFG {   // static int MAX = 100;  // Function to count all sorted rows in   // a matrix  static int sortedCount(int []mat int r  int c)  {  int result = 0; // Initialize result  // Start from left side of matrix to  // count increasing order rows  for (int i = 0; i < r; i++) {    // Check if there is any pair of  // element that are not in  // increasing order.  int j;  for (j = 0; j < c - 1; j++)  if (mat[ij + 1] <= mat[ij])  break;  // If the loop didn't break (All  // elements of current row were   // in increasing order)  if (j == c - 1)  result++;  }  // Start from right side of matrix   // to count increasing order rows   // ( reference to left these are in   // decreasing order )  for (int i = 0; i < r; i++) {    // Check if there is any pair   // of element that are not in  // decreasing order.  int j;  for (j = c - 1; j > 0; j--)  if (mat[ij - 1] <= mat[ij])  break;  // Note c > 1 condition is   // required to make sure that a   // single column row is not   // counted twice (Note that a   // single column row is sorted  // both in increasing and  // decreasing order)  if (c > 1 && j == 0)  result++;  }  return result;  }    // Driver code  public static void Main()  {  int m = 4 n = 5;  int []mat = { { 1 2 3 4 5 }  { 4 3 1 2 6 }  { 8 7 6 5 4 }  { 5 7 8 9 10 } };    Console.WriteLine(  sortedCount(mat m n));  } } // This code is contributed by anuj_67. 
JavaScript
<script> // Javascript program to find number of sorted rows    let MAX = 100;    // Function to count all sorted rows in a matrix  function sortedCount(matrc)  {  let result = 0; // Initialize result    // Start from left side of matrix to  // count increasing order rows  for (let i = 0; i < r; i++) {    // Check if there is any pair of element  // that are not in increasing order.  let j;  for (j = 0; j < c - 1; j++)  if (mat[i][j + 1] <= mat[i][j])  break;    // If the loop didn't break (All elements  // of current row were in increasing order)  if (j == c - 1)  result++;  }    // Start from right side of matrix to  // count increasing order rows ( reference  // to left these are in decreasing order )  for (let i = 0; i < r; i++) {    // Check if there is any pair of element  // that are not in decreasing order.  let j;  for (j = c - 1; j > 0; j--)  if (mat[i][j - 1] <= mat[i][j])  break;    // Note c > 1 condition is required to make  // sure that a single column row is not counted  // twice (Note that a single column row is sorted  // both in increasing and decreasing order)  if (c > 1 && j == 0)  result++;  }  return result;  }  // Driver code   let m = 4 n = 5;    let mat = [[1 2 3 4 5]  [4 3 1 2 6]  [8 7 6 5 4]  [5 7 8 9 10]]  document.write(sortedCount(mat m n))    // This code is contributed by unknown2108 </script> 
PHP
 // PHP program to find  // number of sorted rows $MAX = 100; // Function to count all  // sorted rows in a matrix function sortedCount($mat $r $c) { // Initialize result $result = 0; // Start from left side of // matrix to count increasing  // order rows for ( $i = 0; $i < $r; $i++) { // Check if there is any  // pair of element that  // are not in increasing order. $j; for ($j = 0; $j < $c - 1; $j++) if ($mat[$i][$j + 1] <= $mat[$i][$j]) break; // If the loop didn't break  // (All elements of current  // row were in increasing order) if ($j == $c - 1) $result++; } // Start from right side of  // matrix to count increasing  // order rows ( reference to left // these are in decreasing order ) for ($i = 0; $i < $r; $i++) { // Check if there is any pair  // of element that are not // in decreasing order. $j; for ($j = $c - 1; $j > 0; $j--) if ($mat[$i][$j - 1] <= $mat[$i][$j]) break; // Note c > 1 condition is  // required to make sure that  // a single column row is not  // counted twice (Note that a  // single column row is sorted // both in increasing and  // decreasing order)  if ($c > 1 && $j == 0) $result++; } return $result; } // Driver Code $m = 4; $n = 5; $mat = array(array(1 2 3 4 5) array(4 3 1 2 6) array(8 7 6 5 4) array(5 7 8 9 10)); echo sortedCount($mat $m $n); // This code is contributed by anuj_67. ?> 

Uitvoer
3

Tijdcomplexiteit: O(m*n) 
Hulpruimte: O(1)

Als u een andere geoptimaliseerde aanpak heeft om dit probleem op te lossen, deel deze dan in de reacties.