第十一次作业

1.实现一个菜单  可以切换 ,可以返回主菜单

主菜单

 1.登录

  2.注册

  3.输出水仙花数

  4.退出程序

请选择:

#include<stdio.h>

#include<string.h>

void mainMenu();

void login();

void regist();

void shuchu();

void tuichu();

main() {

         mainMenu();

}

void mainMenu() {

         int i;

         printf("1.登录\n");

         printf("2.注册\n");

         printf("3.输出水仙花数\n");

         printf("4.退出程序\n");

         scanf("%d", &i);

         switch (i) {

         case 1:

                  login();

                  break;

         case 2:

                  regist();

                  break;

         case 3:

                  shuchu();

                  break;

         case 4:

                  tuichu();

                  break;

         }

}

void login() {

         char uname[20], upwd[20];

         printf("请输入用户名");

         scanf("%s", uname);

         printf("请输入密码");

         scanf("%s", upwd);

         if (strcmp(uname, "admin") == 0 && strcmp(upwd, "admin") == 0) {

                  printf("登陆成功");

         }

         else {

                  printf("登录失败");

         }

         returnToMain();

}

void regist() {

         char uname[20], upwd1[20], upwd2[20];

         printf("*****欢迎注册*****\n");

         printf("请输入用户名");

         scanf("%s", uname);

         printf("请输入密码");

         scanf("%s", upwd1);

         printf("请再次输入密码");

         scanf("%s", upwd2);

         if (strcmp(upwd1, upwd2) == 0) {

                  printf("注册成功");

         }

         else {

                  printf("注册失败");

         }

         returnToMain();

}

void shuchu() {

         int a, b, c;

         int j = 100;

         while (j < 1000) {

                  a = j / 100;

                  b = j % 100 / 10;

                  c = j % 10;

                  if (j == a * a * a + b * b * b + c * c * c)

                          printf("%4d", j);

                  j++;

         }

}

void tuichu() {

         printf("退出程序");

}

}

 

 

 

2.使用函数,求2个数的最大值,并调用.

#include<stdio.h>

int max(int a,int b) {

    int c;

    if (a > b)

         c = a;

    else

         c = b;

    return c;

}

int main() {

    int max(int a, int b);

         int a, b, c;

         printf("输入两个数");

         scanf_s("%d%d", &a, &b);

         c = max(a, b);

         printf("最大的是%d", c);

         return 0;

}

 

3.使用递归函数,求阶乘,并调用求5的阶乘

#include <stdio.h>

int f(int n)

{

if(n==1)

return 1;

return f(n-1)*n;

}

int main()

{

int i;

i=f(5);

printf("结果为%d ",i);

return 0;

}

 

 

 

4.使用函数,判断一个年份是不是闰年,如果是闰年返回1,否则返回0

#include<stdio.h>

int nian(int n) {

    if (n % 4 == 0 && n % 100 != 0 || n % 400 == 0)

         return 1;

    else

         return 0;

}

int main() {

    int n;

    printf("输入月份");

    scanf_s("%d", &n);

    return 0;

}

 

 

5.使用函数,求一个数绝对值,并调用.

#include<stdio.h>

int abs(int a) {

    if (a < 0)

         return -a;

    return a;

}

int main(){

    int a;

    scanf_s("%d", &a);

    printf("绝对值为%d", abs(a));

    return 0;

}