cfdiv2/c/找规律

题目连接

£：若n<4，NO；

£：若n==4,特判，n==5，特判。

£：若n>=6,用2-4组成24，1和5和6组成零，即可。

#include <set>
#include <map>
#include <cmath>
#include <queue>
#include <cstdio>
#include <cstring>
#include <iostream>
#include <algorithm>
using namespace std;
int n;
int main ()
{
    while(scanf("%d",&n)!=EOF)
    {
        if(n<4)
        {
            printf("NO\n");
        }
        else
        {
            printf("YES\n");
            if(n==4)
            {
                cout<<"2 * 4 = 8"<<endl;
                cout<<"3 * 8 = 24"<<endl;
                cout<<"1 * 24 = 24"<<endl;
            }
            else if(n==5)
            {
                cout<<"3 - 1 = 2"<<endl;
                cout<<"2 + 2 = 4"<<endl;
                cout<<"4 * 5 = 20"<<endl;
                cout<<"20 + 4 = 24"<<endl;
            }
            else
            {
                cout<<"1 + 5 = 6"<<endl;
                cout<<"6 - 6 = 0"<<endl;
                for(int i=7;i<=n;i++)
                    cout<<"0 * "<<i<<" = 0"<<endl;
                cout<<"2 * 3 = 6"<<endl;
                cout<<"4 * 6 = 24"<<endl;
                cout<<"24 + 0 = 24"<<endl;
            }
        }
    }
    return 0;
}