比较简单 留个存档

#include<iostream>
#include<stdio.h>
#include<cmath>
using namespace std;
//4-1 4-2 
//P82

// 1 两个物资的交换
void swap()
{
    cout<<"swap:"<<endl;
    int a,b;
    cin>>a>>b;
    int c=a;
    a=b;
    b=c;

    cout<<a<<","<<b<<endl;

}
//2 求一个三位整形数字的各位
void solve1()
{
    cout<<"各位数字："<<endl;
    int num;
    cin>>num;
    while(num)
    {
        cout<<num%10<<" ";
        num/=10;
    }
    cout<<endl;

}
//3 闰年

void solve2()
{
    cout<<"闰年"<<endl;
    int year;
    cin>>year;
    cout<<((year%4==0&&year%100!=0||year%400==0)?"Yes":"No")<<endl;

}
//11 读入10 个数字
//求他们的和 与 积  及其平均值
void solve3()
{
    cout<<"10 个数字"<<endl;
    int n=10;
    double t=n;

    int add=0;
    int mut=1;

    int num;

    while(n--)
    {
        cin>>num;
        add+=num;
        mut*=num;
    }
    printf("%d,%d,%lf",add,mut,add/t);


}

typedef struct
{
    float x;
    float y;

}Point;

void solve4(){
    cout<<"输入两个点求距离："<<endl;
    Point a1,a2;
    cin>>a1.x>>a1.y>>a2.x>>a2.y;

    float ans=sqrt(pow(abs(a1.x-a2.x),2)+pow(abs(a1.y-a2.y),2));
    cout<<ans<<endl;

}
void solve5()
{
    cout<<"输入三个数字 求最大数值"<<endl;
    int cnt=3;
    int n;
    int max=0Xefffffff;

    while(cnt--){
        cin>>n;
        max=n>max?n:max;
    }
    cout<<max<<endl;

}

void endSolve()
{

    //ax^2+bx+c=0
    cout<<"ax^2+bx+c=0求解："<<endl;
    int a,b,c;
    cin>>a>>b>>c;

    if(a==0)
    {
        if(b==0){
            if(c==0)
            {
                cout<<"x为任意数"<<endl;
            }else
            {
                cout<<"等式不成立"<<endl;
            }
        }else{
            if(c==0)//bx=0
            {
                cout<<"x为任意数"<<endl;
            }else //bx+c
            {
                cout<<"x:"<<-(c/(double)b)<<endl;
            }
        }
    }else{
        if(b==0){ 
            if(c==0) //ax=0
            {
                cout<<"x为任意数"<<endl;
            }else //ax+c
            {
                cout<<"x:"<<-(c/(double)a)<<endl;
            }
        }else{
            if(c==0)//ax+bx=x(a+b)=0
            {
                cout<<"x:0"<<endl;
            }else //ax+bx+c
            {
                int dit=b*b-4*a*c;
                if(dit==0)//有两个相同的解 》x=- b/(2a)
                {
                    cout<<"x:"<<-((double)b/2/a)<<endl;
                }else if(dit>0)//x=(-b(+-)根号下dit)/2a
                {
                    cout<<"x1:"<<(-1*b+sqrt(dit))/2/a <<endl;
                    cout<<"x2:"<<(-1*b-sqrt(dit))/2/a <<endl;
                }else if(dit<0)//无实数根 担忧两个共轭复数根
                {
                    cout<<"无实数根 但两个共轭复数根"<<endl;
                }
            }
        }
    }
}

int main()
{


    swap();
    solve1();
    solve2();
    solve3();//1 2 3 4 5 6 7 8 9 10
    solve4();
    solve5();
    endSolve();
    return 0;

}