Submission #1205067

#	Time	Username	Problem	Language	Result	Execution time	Memory
1205067		PlayVoltz	Building 4 (JOI20_building4)	C++20	100 / 100	254 ms	127728 KiB

building4

#include <cstdio>
#include <stdio.h>
#include <stdbool.h>
#include <iostream>
#include <map>
#include <vector>
#include <climits>
#include <stack>
#include <string>
#include <queue>
#include <algorithm>
#include <set>
#include <unordered_set>
#include <unordered_map>
#include <cmath>
#include <cctype>
#include <bitset>
#include <iomanip>
#include <cstring>
#include <numeric>
#include <cassert>
using namespace std;

#define int long long
#define pii pair<int, int>
#define mp make_pair
#define pb push_back
#define fi first
#define se second

pii merge(pii a, pii b){
	if (a.fi==-1)return b;
	else if (b.fi==-1)return a;
	return mp(min(a.fi, b.fi), max(a.se, b.se));
}

pii add(pii a, int b){
	if (a.fi==-1)return a;
	return mp(a.fi+b, a.se+b);
}

int32_t main(){
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	int n;
	cin>>n;
	string ans;
	vector<vector<int> > vect(2*n+1, vector<int>(2, 0));
	vector<vector<pii> > dp(2*n+1, vector<pii>(2, mp(-1, -1)));
	for (int i=1; i<=2*n; ++i)cin>>vect[i][0];
	for (int i=1; i<=2*n; ++i)cin>>vect[i][1];
	dp[0][0]=dp[0][1]=mp(0, 0);
	for (int i=1; i<=2*n; ++i)for (int j=0; j<2; ++j)for (int p=0; p<2; ++p)if (vect[i-1][p]<=vect[i][j])dp[i][j]=merge(dp[i][j], add(dp[i-1][p], j));
	if ((n<dp[2*n][0].fi||dp[2*n][0].se<n)&&(n<dp[2*n][1].fi||dp[2*n][1].se<n)){
		cout<<-1;
		return 0;
	}
	int j=(n<dp[2*n][0].fi||dp[2*n][0].se<n), b=n;
	for (int i=2*n; i; --i){
		ans+=(j?'B':'A');
		b-=j;
		if (dp[i-1][0].fi<=b&&b<=dp[i-1][0].se&&vect[i-1][0]<=vect[i][j])j=0;
		else j=1;
	}
	reverse(ans.begin(), ans.end());
	cout<<ans;
}

• Subtask 1: 11 / 11
• Subtask 2: 89 / 89