Count Entries Equal to X in a Special Matrix in C++

Given a square matrix, mat[][] let the elements of the matrix me mat[i][j] = i*j, the task is to count the number of elements in the matrix is equal to x.

Matrix is like a 2d array in which numbers or elements are represented as rows and columns.

So, let's understand the solution of the problem with the help of examples −

Input −

matrix[row][col] = {
   {1, 2, 3},
   {3, 4, 3},
   {3, 4, 5}};
x = 3

Output −

Count of entries equal to x in a special matrix: 4

Input −

matrix[row][col] = {
   {10, 20, 30},
   {30, 40, 30},
   {30, 40, 50}};
x = 30

Output −

Count of entries equal to x in a special matrix: 4

Approach used in the below program as follows

• Take a matrix mat[][] and x as the input values.

• In function count, we will count the number of entries.

• Traverse the whole matrix, where you find the value of mat[i][j] == x then increment the count by 1.

• Return the value of count and print it as a result.

Example

 Live Demo

#include<bits/stdc++.h>
using namespace std;
#define row 3
#define col 3
//count the entries equal to X
int count (int matrix[row][col], int x){
   int count = 0;
   // traverse and find the factors
   for(int i = 0 ;i<row;i++){
      for(int j = 0; j<col; j++){
         if(matrix[i][j] == x){
            count++;
         }
      }
   }
   // return count
   return count;
}
int main(){
   int matrix[row][col] = {
      {1, 2, 3},
      {3, 4, 3},
      {3, 4, 5}
   };
   int x = 3;
   cout<<"Count of entries equal to x in a special matrix: "<<count(matrix, x);
   return 0;
}

Output

If we run the above code we will get the following output −

Count of entries equal to x in a special matrix: 4