前缀和优化

https://codeforces.com/contest/2053/problem/B

#include<bits/stdc++.h>
#define INF 2e9
using namespace std;

#define endl '\n'
using ll = long long;
using pii = pair<int, int>;
const double PI = acos(-1);
const int N = 2e5 + 10;
const int mod = 1e9 + 7;
int cnt[N*2];
int sum[N*2];
int l[N];
int r[N];
void solve() {
	int n;cin>>n;
	for(int i=1;i<=2*n;i++) sum[i]=cnt[i]=0;//memeset()初始化是2*N,超时了
	for(int i=1;i<=n;i++){
		cin>>l[i]>>r[i];
		if(l[i]==r[i]){
			cnt[l[i]]++;
			sum[l[i]]=1;
		}
	}
	for(int i=2;i<=2*n;i++){
		sum[i]+=sum[i-1];
	}
	for(int i=1;i<=n;i++){
		if(l[i]==r[i]&&cnt[l[i]]>1) cout<<'0';
		else if(l[i]==r[i]) cout<<'1';
		else{
			if((sum[r[i]]-sum[l[i]-1])==(r[i]-l[i]+1)) cout<<'0';
			else cout<<'1';
		}	
	}
	cout<<endl;
}

int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr), cout.tie(nullptr);
	
	int T = 1;
	cin>>T;
	while (T--) {
		solve();
	}
	
	return 0;
}