Apple
链接:https://ac.nowcoder.com/acm/contest/8827/B
来源:牛客网
There are a box of apples,which contains N apples. You’re going to give them to M person. It is required that everyone must be given a positive integer apple, and no one must have the same amount. If it can be done, output “possible”; otherwise output “impossible”.
【代码】
#include <bits/stdc++.h>
using namespace std;
int main(){
int t;cin>>t;
while(t--){
int n,m;cin>>n>>m;
if(n>=(m+1)*m/2){ //如果苹果的个数大于人数m的前m项和
cout<<"possible"<<endl;
}
else cout<<"impossible"<<endl;
}
}
【解题思路】
至少有一种情况是每个人拿到的苹果个数不同,那么,苹果的个数一定要大于人数的前n项和,这样才有机会每个人在1~m中随机取得一个数。