A. Concatenation of Arrays个人题解

https://codeforces.com/problemset/problem/2023/A

经典贪心

先根据每一个组中较小的那个升序，如果相同比较大的那个升序排

#include<bits/stdc++.h>
using namespace std;
#define ll long long
using namespace std;

struct node
{
	int x;
	int y;
}a[200006];
bool cmp(node m,node n)
{
	if(min(m.x,m.y)==min(n.x,n.y)) return max(m.x,m.y)<max(n.x,n.y);
	else return min(m.x,m.y)<min(n.x,n.y);
}
void solve() 
{
	int n;
	cin>>n;
	for(int i=0;i<n;i++)
	{
		cin>>a[i].x>>a[i].y;
	}
	sort(a,a+n,cmp);
	for(int i=0;i<n;i++)
	{
		cout<<a[i].x<<" "<<a[i].y<<" ";
	}cout<<endl;
	
}

int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	ll t;
	cin>>t;
	while(t--)
	{
		solve(); 	
	}
	return 0; 
}