C++(g++ 7.5.0) 解法, 执行用时: 27ms, 内存消耗: 9600K, 提交时间: 2023-05-19 20:09:47

#include<bits/stdc++.h>
using namespace std;
const int N=1e5+10;
const int M=4e6+10;
int c[M];
int a[N];
int n;
int main(){
	scanf("%d",&n);
	for (int i=1;i<=n;i++) scanf("%d",&a[i]);
	for (int i=1;i<=n;i++)
		for (int j=i+1;j<=n;j++) if (!c[a[i]+a[j]]){
			c[a[i]+a[j]]=1; 
		}else {
			puts("YES"); return 0;
		}
	puts("NO");
}

pypy3 解法, 执行用时: 171ms, 内存消耗: 60820K, 提交时间: 2023-05-19 20:15:14

import sys
input = lambda:sys.stdin.readline().strip()
def func():
    n = int(input())
    a = list(map(int, input().split()))
    a.sort()
    h = [0]*(4*10**6+1)
    for i in range(n):
        for j in range(i):
            if h[a[i]+a[j]]:return 1
            h[a[i]+a[j]] = 1
if func():print('YES')
else:print('NO')

C++(clang++ 11.0.1) 解法, 执行用时: 95ms, 内存消耗: 5516K, 提交时间: 2023-05-21 20:50:58

#include<bits/stdc++.h>
using namespace std;
	int main()
	{
		int n;
		cin>>n;
		int i,a[n],j;
		map<int,int>p;
		for(i=0;i<n;i++)
		{
			cin>>a[i];
		}
		for(i=0;i<n;i++)
		for(j=i+1;j<n;j++)
		{
			if(p[a[i]+a[j]]==0)p[a[i]+a[j]]=1;
			else 
			{
				cout<<"YES"<<endl;return 0;
			}
		}
		cout<<"NO"<<endl;
	}

Python3 解法, 执行用时: 222ms, 内存消耗: 55576K, 提交时间: 2023-05-20 08:44:17

n = int(input())

f = [0] * 5000000

a = list(map(int, input().split()))

for i in range(n):
    for j in range(i + 1, n):
        if f[a[i] + a[j]]:
            print("YES")
            exit(0)
        f[a[i] + a[j]] = 1

print("NO")