1,計算n的結城,
#include<stdio.h>
int main() //代碼入口
{
int a = 0;
int n = 0;
int p = 1;
scanf("%d", &n);//scanf取n的地址,輸入n的值,開始for循環
for (a = 1;a <= n;a++) {
p = p * a;
}
printf("p=%d ", p);//輸出
}
2,計算 1!+2!+3!+4!+.....+10!
#include<stdio.h>
int main()
{
int i = 0, n, p = 1;
for (n = 1;n <=10;n++)
{
p = p * n;
i = i + p;
}
printf("1!+2!+3!+...+10!=%d", i);
return 0;
}
3,在一個有序數組中找出具体的某个数字n,编写int binsearch(int x,int v[],int n);功reng;在v[0]<v[1]<=v[2]<=......<=v[n-1]的数组中查找x,
#include<stdio.h>
int main()
{
int arr[] = {1,2,3,4,5,6,8,9,10,11};
int k = 7;
int sz = sizeof(arr)/sizeof(arr[0]);//计算元素个数
int left = 0;//左下标
int right = sz-1;//右下标
while(left<=right)
{
int mid = (left+right)/2;
if(arr[mid] > k)
{
right = mid-1;
}
else if(arr[mid] < k)
{
left = mid+1;
}
else
{
printf("找到了,下标是:%d\n", mid);
break;
}
}
if(left>right)
{
printf("找不到\n");
}
return 0;
}
4,编写代码,演绎多个数字从两端移动,向中间汇聚
#include<stdio.h>
#include <string.h>
#include <windows.h>
#include <stdlib.h>
int main()
{
char arr1[] = "welcome to bit!!!!!!";
char arr2[] = "####################";
int left = 0;
//int right = sizeof(arr1)/sizeof(arr1[0])-2;//err
int right = strlen(arr1)-1;
while(left<=right)
{
arr2[left] = arr1[left];
arr2[right] = arr1[right];
printf("%s\n", arr2);
//休息一秒
Sleep(1000);
system("cls");//执行系统命令的一个函数-cls - 清空屏幕
left++;
right--;
}
printf("%s\n", arr2);
return 0;
}
5,编写代码实现,模拟用户登录情景,并且只能登录三次,(只允许输入三次,如果密码正确提示登录成功,如果密码错误,则提示退出程序
int main()
{
int i = 0;
char password[20] = {0};
for(i=0; i<3; i++)
{
printf("请输入密码:>");
scanf("%s", password);
if(strcmp(password, "123456") == 0)//== 不能用来比较两个字符串是否相等,应该使用一个库函数-strcmp
{
printf("登录成功\n");
break;
}
else
{
printf("密码错误\n");
}
}
if(i == 3)
printf("三次密码均错误,退出程序\n");
return 0;
}