２行３列の行列を加算するプログラム

#include <stdio.h>

int main(void)
{
    int i, j;
    int ma[2][3] = { {1, 2, 3}, {4, 5, 6} };
    int mb[2][3] = { {6, 3, 4}, {5, 1, 2} };
    int mc[2][3] = { 0 };
    
    for (i = 0; i < 2; i++)
        for (j = 0; j < 3; j++)
            mc[i][j] = ma[i][j] + mb[i][j];
        
    for (i = 0; i < 2; i++) {
        for (j = 0; j < 3; j++)
            printf("%3d", mc[i][j]);
        putchar('\n');
    }
    
    return (0);
}

実行結果

7 5 7
9 6 8