c - How to get access to each row and column in rectangular matrix

Question

Good day to everybody. My task is to determine if a rectangular matrix has two rows of positive elements. I write the code below. At end I try to chect statement about positive row, but it's not working at all. Please explain me how to correct get the access to the each row and column in matrix, and meaybe edit my code.

#include <stdio.h>
#include <conio.h>
#include <locale.h>

#define M 3
#define N 4

int main(){
    setlocale(LC_ALL, "Rus");
    float a[M][N]; //set matrix with 3 row and 4 column
    int i, j;     // row and column index
    int count;
    for (i = 0; i < M; i++){
        for (j = 0; j < N; j++)
            scanf_s("%f", &a[i][j]);
    }
    for (i = 0; i < M; i++){
        printf("%d-я строка:", i + 1);
        for (j = 0; j < N; j++)
            printf("%f", a[i][j]);
        printf("
");
    }
    count = 0;
    for (i = 0; i < M; i++){
        for (j = 0; j < N; j++)
            if (a[i][j] > 0){
                count++;
                printf("%d", count);
        }
    }
    _getch();
    return 0;
}

question from:https://stackoverflow.com/questions/65867914/how-to-get-access-to-each-row-and-column-in-rectangular-matrix

Answer 1

When counting the number of positive elements in a row, you need to set the count back to zero for each row.

So instead of:

count = 0;
for (i = 0; i < M; i++){
    for (j = 0; j < N; j++)
        if (a[i][j] > 0){
            count++;
            printf("%d", count);
    }
}

you need

for (i = 0; i < M; i++){
    count = 0;
    for (j = 0; j < N; j++) {
        if (a[i][j] > 0){
            count++;
        }
    }
    printf("row %d has %d positive elements
", i, count);
}