写进去,再比较,然后打印,就这么三步:

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

int main()
{
    char id[20],code[20];
    char zz[] = "admin";
    while(scanf("%s %s",&id,&code) != EOF)
    {
        if(strcmp(id,zz)==0&&strcmp(code,zz) ==0)
        {
            printf("Login Success!\n");
        }
        else
        {
            printf("Login Fail!\n");
        }
    }
    return 0;
}