c语言：用户输入用户名和密码，判断是否合法用户（用户名为abc，密码为123456）

Question

如果合法，显示"welcome to use the software",否则要求重新输入，允许输入3次，若3次都错，显示“password error!you can not use software".

Answer 1

#include <stdio.h>;
#include <stdlib.h>;

main(){
int key,i;
printf("请输入密码：\n");
scanf("%d",&key);
if(key==123)
printf("welcome to use the software!\n");
else{
printf("请输入密码：");
scanf("%d",&key);
if(key==123)
printf("welcome to use the software!\n");
else{
printf("请输入密码：");
scanf("%d",&key);
if(key==123)
printf("welcome to use the software!\n");
else printf("password error!you can not use software!\n");
}
}
system("pause");
}

这是最笨的方法，它可用循环实现，你自己想想去做