Submission #221471

#	Time	Username	Problem	Language	Result	Execution time	Memory
221471		raghav0307	Building 4 (JOI20_building4)	C++14	0 / 100	10 ms	8320 KiB

building4

/*raghav0307 - Raghav Gupta*/
 
#include <bits/stdc++.h>
using namespace std;
 
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
 
#define ff first
#define ss second
#define pb push_back
#define fast_io() ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
#define int ll

typedef long long ll;
typedef pair<int, int> pii;
typedef long double ld;
 
typedef tree<int,null_type,less<int>,rb_tree_tag, tree_order_statistics_node_update> indexed_set;

const int MAXN = 1e6 + 5;
int a[MAXN], b[MAXN];
int ans[MAXN];

signed main(){
	fast_io();
	
	int n;	cin >> n;
	for(int i = 0; i < 2*n; i++)
		cin >> a[i];
	for(int i = 0; i < 2*n; i++)
		cin >> b[i];
	
	memset(ans, -1, sizeof(ans));

	int x = 0, y = 0;
	int last = min(a[0], b[0]);
	for(int i = 1; i < 2*n; i++){
		if(a[i] < last and b[i] < last){
			cout << "-1\n";
			return 0;
		}
		else if(a[i] < last){
			y++;
			last = b[i];
			ans[i] = 2;
		}
		else if(b[i] < last){
			x++;
			last = a[i];
			ans[i] = 1;
		}
		else{
			last = min(a[i], b[i]);
		}
	}

	last = max(a[2*n-1], b[2*n-1]);
	for(int i = 2*n-2; i >= 0; i--){
		if(a[i] > last and b[i] > last){
			cout << "-1\n";
			return 0;
		}
		else if(a[i] > last){
			y++;
			last = b[i];
			ans[i] = 2;
		}
		else if(b[i] > last){
			x++;
			last = a[i];
			ans[i] = 1;
		}
		else{
			last = max(a[i], b[i]);
		}
	}

	for(int i = 0; i < 2*n; i++){
		if(ans[i] == 1){
			cout << "A";
		}
		else if(ans[i] == 2){
			cout << "B";
		}
		else if(x < n and y < n){
			if(a[i] <= b[i]){
				cout << "A";
				x++;
			}
			else{
				cout << "B";
				y++;
			}
		}
		else if(x < n){
			cout << "A";
			x++;
		}
		else{
			cout << "B";
			y++;
		}
	}
	cout << "\n";

	return 0;
}

• Subtask 1: 0 / 11
• Subtask 2: 0 / 89