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Submission #328606

# Submission time Handle Problem Language Result Execution time Memory
328606 2020-11-17T10:44:38 Z dolphingarlic Nafta (COI15_nafta) C++14
100 / 100
 450 ms 123364 KB 
#include <bits/stdc++.h>
typedef long long ll;
using namespace std;

int n, m;
char grid[2001][2001];
bool visited[2001][2001];
int dx[4]{1, -1, 0, 0}, dy[4]{0, 0, 1, -1};
int bit[2001], diff[2001][2001], dp[2001][2001];

bool inside(int x, int y) {
    return x && y && x <= n && y <= m && !visited[x][y] && grid[x][y] != '.';
}

tuple<int, int, int> get_oil(int x, int y) {
    tuple<int, int, int> ret = {y, y, grid[x][y] - '0'};
    visited[x][y] = true;
    for (int i = 0; i < 4; i++) if (inside(x + dx[i], y + dy[i])) {
        tuple<int, int, int> pot = get_oil(x + dx[i], y + dy[i]);
        get<0>(ret) = min(get<0>(ret), get<0>(pot));
        get<1>(ret) = max(get<1>(ret), get<1>(pot));
        get<2>(ret) += get<2>(pot);
    }
    return ret;
}

void update(int pos, int val) {
    for (; pos <= m; pos += pos & -pos) bit[pos] += val;
}

int query(int pos) {
    int ans = 0;
    for (; pos; pos -= pos & -pos) ans += bit[pos];
    return ans;
}

void solve(int placed, int l, int r = m, int opt_l = 0, int opt_r = m - 1) {
    int mid = (l + r) / 2;
    int opt = -1;
    for (int i = opt_l; i <= min(mid - 1, opt_r); i++) {
        if (dp[placed - 1][i] + diff[mid][i] > dp[placed][mid]) {
            dp[placed][mid] = dp[placed - 1][i] + diff[mid][i];
            opt = i;
        }
    }
    if (l != r) {
        solve(placed, l, mid, opt_l, opt);
        solve(placed, mid + 1, r, opt, opt_r);
    }
}

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cin >> n >> m;
    for (int i = 1; i <= n; i++) for (int j = 1; j <= m; j++) {
        cin >> grid[i][j];
    }
    vector<tuple<int, int, int>> oil;
    for (int i = 1; i <= n; i++) for (int j = 1; j <= m; j++) {
        if (inside(i, j)) {
            int l, r, val;
            tie(l, r, val) = get_oil(i, j);
            oil.push_back({l, l, val});
            oil.push_back({r + 1, l, -val});
        }
    }
    sort(oil.begin(), oil.end());
    for (int i = 1, ptr = 0; i <= m; i++) {
        while (get<0>(oil[ptr]) <= i) {
            update(get<1>(oil[ptr]), get<2>(oil[ptr]));
            ptr++;
        }
        for (int j = 0; j < i; j++) diff[i][j] = query(i) - query(j);
    }

    for (int i = 1; i <= m; i++) {
        solve(i, i);
        cout << *max_element(dp[i] + 1, dp[i] + m + 1) << '\n';
    }
    return 0;
}

Subtask #1
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 1004 KB Output is correct
2 Correct 1 ms 1004 KB Output is correct
3 Correct 1 ms 1004 KB Output is correct
4 Correct 1 ms 1004 KB Output is correct
5 Correct 1 ms 1004 KB Output is correct
6 Correct 1 ms 1004 KB Output is correct

Subtask #2
23.0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 1004 KB Output is correct
2 Correct 1 ms 1004 KB Output is correct
3 Correct 1 ms 1004 KB Output is correct
4 Correct 1 ms 1004 KB Output is correct
5 Correct 1 ms 1004 KB Output is correct
6 Correct 1 ms 1004 KB Output is correct
7 Correct 12 ms 4840 KB Output is correct
8 Correct 11 ms 4652 KB Output is correct
9 Correct 15 ms 6380 KB Output is correct
10 Correct 10 ms 4652 KB Output is correct
11 Correct 9 ms 4588 KB Output is correct
12 Correct 8 ms 4460 KB Output is correct

Subtask #3
66.0 / 66.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 1004 KB Output is correct
2 Correct 1 ms 1004 KB Output is correct
3 Correct 1 ms 1004 KB Output is correct
4 Correct 1 ms 1004 KB Output is correct
5 Correct 1 ms 1004 KB Output is correct
6 Correct 1 ms 1004 KB Output is correct
7 Correct 12 ms 4840 KB Output is correct
8 Correct 11 ms 4652 KB Output is correct
9 Correct 15 ms 6380 KB Output is correct
10 Correct 10 ms 4652 KB Output is correct
11 Correct 9 ms 4588 KB Output is correct
12 Correct 8 ms 4460 KB Output is correct
13 Correct 426 ms 49344 KB Output is correct
14 Correct 428 ms 46144 KB Output is correct
15 Correct 450 ms 123364 KB Output is correct
16 Correct 328 ms 45776 KB Output is correct
17 Correct 281 ms 40296 KB Output is correct
18 Correct 263 ms 40204 KB Output is correct