matrix_div_k.c

matrix_div_k.c

#include <stdio.h>
#include <malloc.h>



int sumDivisibleRecursiveAlt(int **matrix, int k, int index, int n) {

     if(index >= n * n) {
        return 0;
     }

     int row = index / n;
     int col = index % n;

     int currentSum = 0;

     if(matrix[row][col] % k == 0) currentSum = matrix[row][col];

     return currentSum + sumDivisibleRecursiveAlt(matrix, k, index + 1, n);
}

//wrapper for recursion alternative
int sumDivByRecursiveAlt(int **matrix, int k, int n) {

     return sumDivisibleRecursiveAlt(matrix, k, 0, n);
}


int sumDivisibleRecursive(int **matrix, int k, int row, int col, int n) {

    if(row >= n) {

       return 0;
    }

    if(col >= n) {

       return sumDivisibleRecursive(matrix, k, row + 1, 0, n);
    }

    int currentSum = 0;

    if(matrix[row][col] % k == 0) currentSum = matrix[row][col];

    return currentSum + sumDivisibleRecursive(matrix, k, row, col+1, n);//0, 1, 3
}


int **readMatrix(int *size) {

    int n;

    printf("Enter the size of square matrix (n x n): ");

    scanf("%d", &n);

    *size = n;

    int **matrix = (int**)malloc(n * sizeof(int*));

    for(int i = 0; i < n; i++) {

        matrix[ i ] = (int*)malloc(n * sizeof(int));
    }

    printf("Enter the matrix elements: \n");

    for(int i = 0; i < n; ++i) {

       printf("Row %d: ", i + 1);

       for(int j = 0; j < n; ++j) {

           scanf("%d", &matrix[i][j]);
       }

    }

    return matrix;
}

void displayMatrix(int **matrix, int n) {

     for(int i = 0; i < n; ++i) {
       for(int j = 0; j < n; ++j) {
          printf("%d\t", matrix[i][j]);
       }
       printf("\n");
     }
}

int main() {

   int n;

   int k;

   int **matrix = readMatrix(&n);

   displayMatrix(matrix, n);

   printf("k = ");
   scanf("%d",&k);

   printf("\nResults: \n");

   printf("Sum using Recursive approach: \n");

   int sumRecursive = sumDivByRecursiveAlt(matrix, k, n);

   printf("sum = %d", sumRecursive);
   
}