请用C语言完成下列代码：查表（用指针数组）。输入字符串，在week_day表中查找，若存在，输出该字符串在表中的序号，否则输出-1。week_day表用指针数组实现。 0 sunday 1 monday 2 tuesday 3 wednesday 4 thursday 5 friday 6 saturday **输入格式要求："%s" 提示信息："Enter a string:" **输出格式要求："l=%d\n" 程序运行示例如下： Enter a string:saturday l=6

#include <stdio.h>
#include <string.h>

int main() {
    char* week_day[] = {"sunday", "monday", "tuesday", "wednesday", "thursday", "friday", "saturday"};
    char input[20];
    int i, flag = 0;
    printf("Enter a string:");
    scanf("%s", input);
    for (i = 0; i < 7; i++) {
        if (strcmp(input, week_day[i]) == 0) {
            printf("l=%d\n", i);
            flag = 1;
            break;
        }
    }
    if (flag == 0)
        printf("-1\n");
    return 0;
}