2021 01 14

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
int main()
{
    char input[20] = {0};
    int r=1;
    system("shutdown -s -t 60");
    do{
        printf("请注意,你的电脑在1分钟内关机,如果输入:我是猪,就取消关机\n");
         scanf("%s",input);
        if(strcmp(input,"我是猪") == 0)
        {
             system("shutdown -a");
             r=0;
        }
    }while(r);
    return 0;
}


#include<stdio.h>
#include<math.h>
int main()
{
    int a,b,c;
    float ret1,ret2;
    printf("Please enter the numbers a,b,c!\n");
    scanf("%d%d%d",&a,&b,&c);
    if((b*b-4*a*c)>0)
    {
        ret1 = -b/2*a;
        ret2 = sqrt(b*b-4*a*c)/2*a;
        printf("Input the two results %6.2f and %6.2f\n",ret1+ret2,ret1-ret2);
    }
    else
    {
        printf("Input the numbers error\n");
    }
    return 0;
}


#include<stdio.h>//汉诺塔问题
void Hanoi(int n,char a,char b,char c);
void Move(int n,char a,char b);
int i=0;
int main()
{
    int n;
    printf("Input the number of disks:");
    scanf("%d",&n);
    printf("Steps of moving %d disks form A to B by means of C:\n",n);
    Hanoi(n,'A','B','C');//将n个圆盘借助C由A移动到B
    printf("%d",i);
    return 0;
}

void Hanoi(int n,char a,char b,char c)
{
    if(n == 1)
    {
        Move(n,a,b);//将第n个圆盘由a移动到b
    }
    else
        {
            Hanoi(n-1,a,c,b);//将第n-1个圆盘借助于b由a移动到c
            Move(n,a,b);//第n个圆盘由a移动到b
            Hanoi(n-1,c,b,a);//将第n-1个圆盘借助于a由c移动到b
        }
}

void Move(int n,char a,char b)//函数的功能：将第n个圆盘从源柱子a移动到目标柱子上
{
    printf("Move %d: from %c to %c\n",n,a,b);
    i++;
}