oj.uz

Submission #679230

# Submission time Handle Problem Language Result Execution time Memory
679230 2023-01-07T19:43:20 Z bebra Boat (APIO16_boat) C++17
9 / 100
 2000 ms 18796 KB 
#define _GLIBCXX_DEBUG_PEDANTIC
#include <bits/stdc++.h>
using namespace std;

#define dbg(x) cerr << #x << ": " << x << endl;


struct Seg {
    int l;
    int r;

    Seg(int _l = -1, int _r = -1) : l(_l), r(_r) {}


    bool empty() const {
        return r - l + 1 <= 0;
    }

    bool operator<(const Seg& other) const {
        return tie(l, r) < tie(other.l, other.r);
    }

    bool operator==(const Seg& other) const {
        return tie(l, r) == tie(other.l, other.r);
    }

    friend Seg intersect(const Seg& lhs, const Seg& rhs) {
        return {max(lhs.l, rhs.l), min(lhs.r, rhs.r)};
    }
};


const int MOD = 1e9 + 7;
const int INV2 = 500000004;

int add(int a, int b) {
    int res = a + b;
    if (res >= MOD) res -= MOD;
    return res;
}

int mul(long long a, int b) {
    return a * b % MOD;
}

const int MAX_N = 500 + 1;
Seg segs[MAX_N];
int dp[MAX_N][MAX_N * MAX_N];
int main_idx[MAX_N];


int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    int n;
    cin >> n;
    for (int i = 1; i <= n; ++i) {
        cin >> segs[i].l >> segs[i].r;
    }
    
    vector<Seg> states;
    for (int i = 1; i <= n; ++i) {
        for (int j = 1; j <= n; ++j) {
            if (segs[i].l <= segs[j].r) {
                states.emplace_back(segs[i].l, segs[j].r);
            }
            if (segs[i].l <= segs[j].l - 1) {
                states.emplace_back(segs[i].l, segs[j].l - 1);
            }
        }
    }
    sort(states.begin(), states.end());
    states.resize(unique(states.begin(), states.end()) - states.begin());
    int m = states.size();

    segs[0] = {-1, -1};
    dp[0][0] = 1;
    int ans = 0;
    for (int i = 1; i <= n; ++i) {
        main_idx[i] = lower_bound(states.begin(), states.end(), segs[i]) - states.begin();

        for (int j = 0; j < m; ++j) {
            auto [l1, r1] = states[j];
            if (segs[i].l > l1 || r1 > segs[i].r) continue;
            for (int k = 0; k < i; ++k) {
                auto [l2, r2] = segs[k];
                if (r1 < l2) {
                    continue;
                }
                if (r2 < l1) {
                    dp[i][j] = add(dp[i][j], mul(dp[k][main_idx[k]], r1 - l1 + 1));
                    continue;
                }
                auto [l3, r3] = intersect(states[j], segs[k]);

                dp[i][j] = add(dp[i][j], mul(dp[k][main_idx[k]], r1 - r3));

                int idx1 = lower_bound(states.begin(), states.end(), Seg{l3, r3}) - states.begin();
                dp[i][j] = add(dp[i][j], mul(dp[k][idx1], mul(r3 - l3, INV2)));

                if (l3 - 1 >= l2) {
                    int idx2 = lower_bound(states.begin(), states.end(), Seg{l2, l3 - 1}) - states.begin();
                    dp[i][j] = add(dp[i][j], mul(r3 - l1 + 1, dp[k][idx2]));
                }
            }
        }

        ans = add(ans, dp[i][main_idx[i]]);
    }
    cout << ans << '\n';
    return 0;
}

Subtask #1
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 124 ms 5308 KB Output is correct
2 Correct 118 ms 5376 KB Output is correct
3 Correct 115 ms 5364 KB Output is correct
4 Correct 114 ms 5316 KB Output is correct
5 Correct 125 ms 5252 KB Output is correct
6 Correct 113 ms 5352 KB Output is correct
7 Correct 111 ms 5260 KB Output is correct
8 Correct 112 ms 5368 KB Output is correct
9 Correct 118 ms 5352 KB Output is correct
10 Correct 115 ms 5288 KB Output is correct
11 Correct 119 ms 5480 KB Output is correct
12 Correct 111 ms 5376 KB Output is correct
13 Correct 115 ms 5320 KB Output is correct
14 Correct 114 ms 5268 KB Output is correct
15 Correct 112 ms 5292 KB Output is correct
16 Correct 23 ms 5384 KB Output is correct
17 Correct 22 ms 5392 KB Output is correct
18 Correct 22 ms 5400 KB Output is correct
19 Correct 21 ms 5396 KB Output is correct
20 Correct 22 ms 5324 KB Output is correct

Subtask #2
0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 124 ms 5308 KB Output is correct
2 Correct 118 ms 5376 KB Output is correct
3 Correct 115 ms 5364 KB Output is correct
4 Correct 114 ms 5316 KB Output is correct
5 Correct 125 ms 5252 KB Output is correct
6 Correct 113 ms 5352 KB Output is correct
7 Correct 111 ms 5260 KB Output is correct
8 Correct 112 ms 5368 KB Output is correct
9 Correct 118 ms 5352 KB Output is correct
10 Correct 115 ms 5288 KB Output is correct
11 Correct 119 ms 5480 KB Output is correct
12 Correct 111 ms 5376 KB Output is correct
13 Correct 115 ms 5320 KB Output is correct
14 Correct 114 ms 5268 KB Output is correct
15 Correct 112 ms 5292 KB Output is correct
16 Correct 23 ms 5384 KB Output is correct
17 Correct 22 ms 5392 KB Output is correct
18 Correct 22 ms 5400 KB Output is correct
19 Correct 21 ms 5396 KB Output is correct
20 Correct 22 ms 5324 KB Output is correct
21 Execution timed out 2072 ms 18796 KB Time limit exceeded
22 Halted 0 ms 0 KB -

Subtask #3
0 / 27.0

# Verdict Execution time Memory Grader output
1 Incorrect 429 ms 2744 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #4
0 / 42.0

# Verdict Execution time Memory Grader output
1 Correct 124 ms 5308 KB Output is correct
2 Correct 118 ms 5376 KB Output is correct
3 Correct 115 ms 5364 KB Output is correct
4 Correct 114 ms 5316 KB Output is correct
5 Correct 125 ms 5252 KB Output is correct
6 Correct 113 ms 5352 KB Output is correct
7 Correct 111 ms 5260 KB Output is correct
8 Correct 112 ms 5368 KB Output is correct
9 Correct 118 ms 5352 KB Output is correct
10 Correct 115 ms 5288 KB Output is correct
11 Correct 119 ms 5480 KB Output is correct
12 Correct 111 ms 5376 KB Output is correct
13 Correct 115 ms 5320 KB Output is correct
14 Correct 114 ms 5268 KB Output is correct
15 Correct 112 ms 5292 KB Output is correct
16 Correct 23 ms 5384 KB Output is correct
17 Correct 22 ms 5392 KB Output is correct
18 Correct 22 ms 5400 KB Output is correct
19 Correct 21 ms 5396 KB Output is correct
20 Correct 22 ms 5324 KB Output is correct
21 Execution timed out 2072 ms 18796 KB Time limit exceeded
22 Halted 0 ms 0 KB -