제출 #359321

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
359321		valerikk	Building 4 (JOI20_building4)	C++17	0 / 100	1 ms	492 KiB

building4

#include <bits/stdc++.h>

using namespace std;

const int N = 1e5 + 7, INF = 1e9 + 10;

int n, a[N][2];
int mn[N][2], mx[N][2];

int main() {
#ifdef LOCAL
    freopen("input.txt", "r", stdin);
#endif
    ios::sync_with_stdio(false);
    cin.tie(0);
    cin >> n;
    a[0][0] = a[0][1] = 0;
    for (int i = 0; i < 2; i++) {
        for (int j = 1; j <= 2 * n; j++) cin >> a[j][i];
    }
    for (int i = 1; i <= 2 * n; i++) {
        for (int j = 0; j < 2; j++) {
            mn[i][j] = INF;
            mx[i][j] = -INF;
        }
    }
    for (int i = 0; i < 2; i++) mn[0][i] = mx[0][i] = 0;
    for (int i = 1; i <= 2 * n; i++) {
        for (int j = 0; j < 2; j++) {
            for (int k = 0; k < 2; k++) {
                if (a[i - 1][k] <= a[i][j]) {
                    if (mn[i - 1][k] != INF) mn[i][j] = min(mn[i][j], mn[i - 1][k] + j);
                    if (mx[i - 1][k] != -INF) mx[i][j] = max(mx[i][j], mx[i - 1][k] + j);
                }
            }
        }
    }
    int j = -1;
    for (int i = 0; i < 2; i++) {
        if (mn[2 * n][i] <= n && n <= mx[2 * n][i]) {
            j = i;
            break;
        }
    }
    if (j == -1) {
        cout << -1;
        return 0;
    }
    string ans = "";
    int cur = n;
    for (int i = 2 * n; i > 0; i--) {
        cur -= j;
        ans.push_back('A' + j);
        int jj = -1;
        for (int k = 0; k < 2; k++) {
            if (mn[i - 1][k] <= cur && cur <= mx[i - 1][k]) {
                jj = k;
                break;
            }
        }
        assert(jj != -1);
    }
    reverse(ans.begin(), ans.end());
    cout << ans << endl;
    return 0;
}

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