Submission #810188

#	Time	Username	Problem	Language	Result	Execution time	Memory
810188		vjudge1	Building 4 (JOI20_building4)	C++17	11 / 100	2028 ms	16172 KiB

building4

#include<bits/stdc++.h>

using namespace std;
using ll = long long;

const int N = 2e3 + 10;

bool dp[2 * N][N][2] = {};
int a[2 * N][2];

int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);cout.tie(0);
    int n;
    cin >> n;
    for(int i = 1; i <= 2 * n; i++)
        cin >> a[i][0];
    for(int i = 1; i <= 2 * n; i++)
        cin >> a[i][1];
    // int ch[n + 1] = {};
    // bool f[n + 1][2] = {};
    // f[1][0] = f[1][1] = 1;
    // for(int i = 1; i <= n; i++)
    dp[0][0][0] = dp[0][0][1] = 1;
    for(int i = 1; i <= 2 * n; i++) {
        for(int k = 0; k <= n; k++) {
            for(int t1 = 0; t1 <= 1; t1++) {
                if(!k && t1) continue;
                for(int t2 = 0; t2 <= 1; t2++) 
                    if(a[i - 1][t2] <= a[i][t1]) dp[i][k][t1] |= dp[i - 1][k - t1][t2];
            }
        }
    }
    if(!(dp[2 * n][n][0] || dp[2 * n][n][1])) {
        cout << -1;
        return 0;
    }
    int k = n, it = (dp[2 * n][n][1]);
    string s;
    for(int i = 2 * n; i >= 1; i--) {
        s += (it ? 'B' : 'A');
        for(int t = 0; t <= 1; t++) {
            if(dp[i - 1][k - it][t] && a[i - 1][t] <= a[i][it]) {
                k -= it;
                it = t;
                break;
            }
        }
    }
    reverse(s.begin(), s.end());
    for(char c : s) 
        cout << c;
}

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