C和指针 练习 1-4

#include 
#define MAX_LEN 1001
int main(void)
{
    char input[MAX_LEN];
    int len;
    char longest[MAX_LEN];
    int longest_len = -1;
    while(gets(input) != NULL && *input != '\0')
    {
        if((len = strlen(input)) > longest_len)
        {
            longest_len = len;
            strcpy(longest, input);
        }
    }
    if(longest_len >= 0)
        puts(longest);
    return 0;
}