제출 #213143

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
213143		MODDI	건물 4 (JOI20_building4)	C++14	100 / 100	1304 ms	53180 KiB

building4

#include <bits/stdc++.h>
#define ll long long
#define pii pair<int,int>
#define pll pair<ll, ll>
#define vi vector<int>
#define vl vector<ll>
#define vii vector<pii>
#define vll vector<pll>
using namespace std;
const int maxn = 5e5;
int n;
pair<int, char>p[2][2 * maxn];
bool b[2][2 * maxn];
char ans[2 * maxn];
vector<array<int, 4> >r;
int main()
{
	cin>>n;
	for(int j : {0 , 1}){
		for(int i = 0; i < 2 * n; i++){
			cin>>p[j][i].first;
			p[j][i].second = 'A' + j;
		}
	}
	for(int i = 0; i < 2 * n; ++i){
		if(p[0][i].first > p[1][i].first)
			swap(p[0][i], p[1][i]);
		if(i > 0){
			if(p[0][i - 1].first > p[1][i].first){
				cout<<-1<<endl;
				return 0;
			}
			if(p[1][i - 1].first > p[1][i].first)
			{
				b[0][i - 1] = 1;
			}
			if(p[0][i].first < p[0][i - 1].first){
				b[1][i] = 1;
			}
			if(p[0][i].first < p[1][i - 1].first){
				if(b[1][i - 1])
					b[1][i] = 1;
			}
		}
	}
	//assert(false);
	for(int i = 2 * n - 1; i ; --i){
		if(p[0][i].first < p[1][i - 1].first){
			if(b[0][i])
				b[0][i - 1] = 1;
		}
		
	}
	//assert(false);
	for(int i = 0; i <2 * n; i++){
		if(b[0][i] && b[1][i]){
			cout<<-1<<endl;
			return 0;
		}
	}
	//assert(false);
	int l[2]={n, n};
	for(int i = 0; i < 2 * n; ++i){
		for(int j : {0, 1}){
			if(b[j][i]){
				ans[i] = p[j][i].second;
				--l[p[j][i].second - 'A'];
			}
		}
	}
	//assert(false);
	int rez1 = 0, rez2 = 0;
	for(int i = 0, j = 0; i < 2 * n; i=j){
		if(b[0][i] || b[1][i]){
			++j;
			continue;
		}
		for(++j; j < 2 * n && !b[0][j] && !b[1][j] && p[0][j].first < p[1][j - 1].first; ++j);
		int c = 0;
		for(int k = i; k < j; ++k){
			c+=p[0][k].second == 'A';
		}
		int mn = c, mx = c;
		for(int k = j - 1; k >= i; --k){
			c-=p[0][k].second == 'A';
			c+=p[1][k].second == 'A';
			mn = min(mn,c);
			mx = max(mx, c);
		}
		r.push_back({i,j, mn, mx});
		rez1 += mn;
		rez2 += mx;
	}
	
	if(l[0] < rez1 || l[0] > rez2)
	{
		cout<<-1<<endl;
		return 0;
	}
	l[0] -= rez1;
	for(array<int, 4> ri : r){
		int need = min(l[0],ri[3] - ri[2]);
		l[0]-=need;
		int c = 0;
		for(int k = ri[0]; k < ri[1]; ++k){
			c+=p[0][k].second =='A';
			ans[k] = p[0][k].second;
		}
		if(c - ri[2] == need){
			continue;
		}
		for(int k = ri[1] - 1; k >= ri[0]; --k){
			c-=p[0][k].second == 'A';
			c+=p[1][k].second == 'A';
			ans[k] = p[1][k].second;
			if(c - ri[2] == need){
				break;
			}
		}
	
	}
	for(int i = 0; i < 2 * n; i++){
		cout<<ans[i];
	}
}

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