1.#include<stdio.h>
#include<windows.h>
#include<time.h>
void menu()
{
printf("------------------------------\n");
printf("-----------1. play -----------\n");
printf("-----------0. exit -----------\n");
printf("------------------------------\n");
}
void game()
{
int num = rand() % 100 + 1;
int input=0;
while (1)
{
printf("请输入你猜的数字:");
scanf_s("%d", &input);
if (input < num)
{
printf("猜小了!");
}
else if (input > num)
{
printf("猜大了!");
}
else
{
printf("猜对了!");
printf("\n");
break;
}
}
}
int main()
{
srand((unsigned)time(NULL));
int a = 0;
do
{
menu();
printf("请选择要进行的操作:");
scanf_s("%d", &a);
switch (a)
{
case 1:
game();
break;
case 0:
break;
default:
printf("输入有误,请重新选择!\n");
break;
}
} while (a);
return 0;
}
2.#include<stdio.h>
#include<windows.h>
#include<string.h>
#pragma warning(disable:4996)
int Binsearch(int a[],int num,int x)
{
int right=num-1;
int left = 0;
while (left < right)
{
int mid = (right + left) / 2;
if (x > a[mid])
{
left = mid + 1;
}
else if (x < a[mid])
{
right = mid - 1;
}
else
{
return 1;
}
}
return 0;
}
int main()
{
int a[] = { 1,2,3,4,5,6,7,8,9,10 };
int num = sizeof(a) / sizeof(a[0]);
int x = 0;
printf("请输入要查找的数字:");
scanf("%d", &x);
int tep = Binsearch(a, num, x);
if (tep)
{
printf("数组中有这个数字\n");
}
else
{
printf("数组中不存在这个数字\n");
}
system("pause");
}
3.
#include<stdio.h>
#include<windows.h>
#include<string.h>
const char *name = "zhangsan";
const char *key = "123";
void login()
{
int count = 3;
while (count > 0)
{
char _name[20];
char _key[20];
printf("please enter your name:");
scanf("%s", _name);
printf(" please enter your key:");
scanf("%s", _key);
if (0 == strcmp(name, _name) && 0 == strcmp(key, _key))
{
printf("login success!\n");
break;
}
else
{
printf("you enter message is error!\n");
count--;
printf("you have %d times!\n", count);
}
}
}
int main()
{
login();
system("pause");
}
4.#include<stdio.h>
#include<windows.h>
#pragma warning (disable:4996)
int main()
{
char number;
while (1)
{
scanf("%c", &number);
if (number >= 'a'&&number <= 'z')
{
printf("%c\n", number - 32);
}
else if (number >= 'A'&&number <= 'Z')
{
printf("%c\n", number + 32);
}
else
;
}
system("pause");
return 0;
}