问个问题

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

struct node{
	int t1,t2;
	bool operator <(const node &x)const{
		return x.t2<t2;//随便排的 
	}
}a[6];
map<node,int>mp;
int main(){
	a[1]=node{1,1},a[2]=node{2,3},a[3]=node{2,4},a[4]=node{2,3},a[5]=node{1,3};
	for(int i=1;i<=5;i++){
		if(!mp[a[i]]){
			cout<<i<<" ";
			mp[a[i]]=1;
		}
	}
}

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

pair<int,int>a[6];
map<pair<int,int>,int>mp;
int main(){
	a[1]=make_pair(1,1),a[2]=make_pair(2,3),a[3]=make_pair(2,4);
	a[4]=make_pair(2,3),a[5]=make_pair(1,3);
	for(int i=1;i<=5;i++){
		if(!mp[a[i]]){
			cout<<i<<" ";
			mp[a[i]]=1;
		}
	}
}