求一个给定的4*5矩阵各行的元素之和

以下是求一个给定的4*5矩阵各行的元素之和的C语言代码：

#include <stdio.h>

int main() {
    int matrix[4][5] = {{1, 2, 3, 4, 5},
                        {6, 7, 8, 9, 10},
                        {11, 12, 13, 14, 15},
                        {16, 17, 18, 19, 20}};
    int row_sum[4] = {0};
    for (int i = 0; i < 4; i++) {
        for (int j = 0; j < 5; j++) {
            row_sum[i] += matrix[i][j];
        }
    }
    for (int i = 0; i < 4; i++) {
        printf("第%d行元素之和为：%d\n", i + 1, row_sum[i]);
    }
    return 0;
}