CF914A Perfect Squares

Posted 2020-10-24 一蓑烟雨任生平

CF914A Perfect Squares

题意翻译

给定一组有n个整数的数组a1,a2,…,an.找出这组数中的最大非完全平方数。 完全平方数是指有这样的一个数x,存在整数y,使得x=y^2y2 .

输入格式

第一行输入一个单独的整数n(1<=n<=1000 )，n为该组数的数量。 接下来有n个整数，a1,a2,an(-10^6<=a<=10^6) 数据保证至少存在一个整数是非完全平方数。

题目描述

Given an array a_{1},a_{2},...,a_{n}a1​,a2​,...,an​ of nn integers, find the largest number in the array that is not a perfect square.

A number xx is said to be a perfect square if there exists an integer yy such that x=y^{2}x=y2 .

输入输出格式

输入格式：

 

The first line contains a single integer nn ( 1<=n<=10001<=n<=1000 ) — the number of elements in the array.

The second line contains nn integers a_{1},a_{2},...,a_{n}a1​,a2​,...,an​ ( -10^{6}<=a_{i}<=10^{6}−106<=ai​<=106 ) — the elements of the array.

It is guaranteed that at least one element of the array is not a perfect square.

 

输出格式：

 

Print the largest number in the array which is not a perfect square. It is guaranteed that an answer always exists.

 

输入输出样例

输入样例#1： 复制

2
4 2

输出样例#1： 复制

2

输入样例#2： 复制

8
1 2 4 8 16 32 64 576

输出样例#2： 复制

32

说明

In the first sample case, 44 is a perfect square, so the largest number in the array that is not a perfect square is 22 .

#include<cmath>
#include<cstdio>
#include<cstring>
#include<iostream>
#include<algorithm>
#define MAXN 1001
using namespace std;
int n;
int num[MAXN];
int main(){
    scanf("%d",&n);
    for(int i=1;i<=n;i++)
        scanf("%d",&num[i]);
    sort(num+1,num+1+n);
    for(int i=n;i>=1;i--){
        int k=sqrt(num[i]);
        if(k*k!=num[i]){
            cout<<num[i];
            return 0;
        }
    }
}