oj.uz

Submission #770860

# Submission time Handle Problem Language Result Execution time Memory
770860 2023-07-02T05:06:10 Z PurpleCrayon Building 4 (JOI20_building4) C++17
100 / 100
 205 ms 45348 KB 
#include <bits/stdc++.h>
using namespace std;

#define sz(v) int(v.size())
#define ar array
typedef long long ll;
const int N = 1e6+10, MOD = 1e9+7;

// some are switchable, but only if the next thing switches (or if it's the tail end)
// you can just start from the end and swithc stuff while you need to

int n, a[N][2];
ar<int, 2> dp[N][2];

void add_self(ar<int, 2>& x, ar<int, 2> y, int delta) {
    y[0] += delta;
    y[1] += delta;
    x[0] = min(x[0], y[0]);
    x[1] = max(x[1], y[1]);
}

void solve() {
    cin >> n;
    for (int j = 0; j < 2; j++) {
        for (int i = 0; i < 2 * n; i++) cin >> a[i][j];
    }

    dp[0][0] = {-1, -1};
    dp[0][1] = {1, 1};
    for (int i = 1; i < 2 * n; i++) {
        // 1 if you take b, -1 if you take a
        dp[i][0] = {MOD, -MOD};
        dp[i][1] = {MOD, -MOD};

        for (int x = 0; x < 2; x++) {
            for (int y = 0; y < 2; y++) {
                if (a[i-1][x] <= a[i][y]) {
                    add_self(dp[i][y], dp[i-1][x], (y ? +1 : -1));
                }
            }
        }
    }

    int last = -1;
    for (int x : {0, 1}) if (dp[2*n-1][x][0] <= 0 && 0 <= dp[2*n-1][x][1]) last = x;
    if (last == -1) {
        cout << -1 << '\n';
        return;
    }


    string ans(2 * n, '?');
    int start = 0;
    for (int i = 2*n-1; i >= 0; i--) {
        ans[i] = last + 'A';
        if (!i) break;
        start -= (last ? +1 : -1);

        for (int x : {0, 1}) {
            if (a[i-1][x] <= a[i][last] && dp[i-1][x][0] <= start && start <= dp[i-1][x][1]) {
                last = x;
                break;
            }
        }
    }

    cout << ans << '\n';
}

int main() {
    ios::sync_with_stdio(false); cin.tie(0);
    int T = 1;
    // cin >> T;
    while (T--) solve();
}

Subtask #1
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 1 ms 340 KB Output is correct
7 Correct 1 ms 340 KB Output is correct
8 Correct 1 ms 340 KB Output is correct
9 Correct 1 ms 364 KB Output is correct
10 Correct 1 ms 340 KB Output is correct
11 Correct 1 ms 340 KB Output is correct
12 Correct 1 ms 340 KB Output is correct
13 Correct 1 ms 340 KB Output is correct
14 Correct 1 ms 340 KB Output is correct
15 Correct 1 ms 340 KB Output is correct
16 Correct 1 ms 340 KB Output is correct
17 Correct 1 ms 432 KB Output is correct
18 Correct 1 ms 340 KB Output is correct
19 Correct 1 ms 340 KB Output is correct
20 Correct 1 ms 340 KB Output is correct
21 Correct 1 ms 340 KB Output is correct
22 Correct 1 ms 340 KB Output is correct
23 Correct 1 ms 340 KB Output is correct
24 Correct 1 ms 340 KB Output is correct
25 Correct 1 ms 340 KB Output is correct
26 Correct 1 ms 340 KB Output is correct
27 Correct 1 ms 340 KB Output is correct
28 Correct 1 ms 340 KB Output is correct
29 Correct 1 ms 340 KB Output is correct
30 Correct 1 ms 340 KB Output is correct
31 Correct 1 ms 340 KB Output is correct
32 Correct 1 ms 340 KB Output is correct
33 Correct 1 ms 340 KB Output is correct

Subtask #2
89.0 / 89.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 1 ms 340 KB Output is correct
7 Correct 1 ms 340 KB Output is correct
8 Correct 1 ms 340 KB Output is correct
9 Correct 1 ms 364 KB Output is correct
10 Correct 1 ms 340 KB Output is correct
11 Correct 1 ms 340 KB Output is correct
12 Correct 1 ms 340 KB Output is correct
13 Correct 1 ms 340 KB Output is correct
14 Correct 1 ms 340 KB Output is correct
15 Correct 1 ms 340 KB Output is correct
16 Correct 1 ms 340 KB Output is correct
17 Correct 1 ms 432 KB Output is correct
18 Correct 1 ms 340 KB Output is correct
19 Correct 1 ms 340 KB Output is correct
20 Correct 1 ms 340 KB Output is correct
21 Correct 1 ms 340 KB Output is correct
22 Correct 1 ms 340 KB Output is correct
23 Correct 1 ms 340 KB Output is correct
24 Correct 1 ms 340 KB Output is correct
25 Correct 1 ms 340 KB Output is correct
26 Correct 1 ms 340 KB Output is correct
27 Correct 1 ms 340 KB Output is correct
28 Correct 1 ms 340 KB Output is correct
29 Correct 1 ms 340 KB Output is correct
30 Correct 1 ms 340 KB Output is correct
31 Correct 1 ms 340 KB Output is correct
32 Correct 1 ms 340 KB Output is correct
33 Correct 1 ms 340 KB Output is correct
34 Correct 185 ms 37468 KB Output is correct
35 Correct 195 ms 41820 KB Output is correct
36 Correct 165 ms 41140 KB Output is correct
37 Correct 205 ms 41988 KB Output is correct
38 Correct 163 ms 42044 KB Output is correct
39 Correct 167 ms 41164 KB Output is correct
40 Correct 163 ms 44620 KB Output is correct
41 Correct 155 ms 42204 KB Output is correct
42 Correct 176 ms 43564 KB Output is correct
43 Correct 183 ms 45128 KB Output is correct
44 Correct 193 ms 45140 KB Output is correct
45 Correct 177 ms 45040 KB Output is correct
46 Correct 166 ms 45276 KB Output is correct
47 Correct 167 ms 44236 KB Output is correct
48 Correct 191 ms 43996 KB Output is correct
49 Correct 168 ms 44768 KB Output is correct
50 Correct 173 ms 44236 KB Output is correct
51 Correct 177 ms 44300 KB Output is correct
52 Correct 124 ms 33360 KB Output is correct
53 Correct 120 ms 33404 KB Output is correct
54 Correct 109 ms 33376 KB Output is correct
55 Correct 116 ms 33168 KB Output is correct
56 Correct 168 ms 45348 KB Output is correct
57 Correct 147 ms 40116 KB Output is correct
58 Correct 143 ms 40268 KB Output is correct
59 Correct 143 ms 40388 KB Output is correct
60 Correct 137 ms 38312 KB Output is correct
61 Correct 157 ms 40996 KB Output is correct
62 Correct 141 ms 40164 KB Output is correct
63 Correct 146 ms 40832 KB Output is correct
64 Correct 136 ms 39356 KB Output is correct
65 Correct 152 ms 40904 KB Output is correct