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답안 #679226

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
679226 2023-01-07T19:14:06 Z bebra Boat (APIO16_boat) C++17
9 / 100
 2000 ms 18964 KB 
#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

# 결과 실행 시간 메모리 Grader output
1 Correct 117 ms 5444 KB Output is correct
2 Correct 122 ms 5536 KB Output is correct
3 Correct 112 ms 5348 KB Output is correct
4 Correct 113 ms 5284 KB Output is correct
5 Correct 114 ms 5308 KB Output is correct
6 Correct 112 ms 5344 KB Output is correct
7 Correct 118 ms 5320 KB Output is correct
8 Correct 113 ms 5332 KB Output is correct
9 Correct 110 ms 5356 KB Output is correct
10 Correct 111 ms 5284 KB Output is correct
11 Correct 117 ms 5264 KB Output is correct
12 Correct 111 ms 5324 KB Output is correct
13 Correct 120 ms 5376 KB Output is correct
14 Correct 110 ms 5296 KB Output is correct
15 Correct 112 ms 5316 KB Output is correct
16 Correct 22 ms 5312 KB Output is correct
17 Correct 22 ms 5392 KB Output is correct
18 Correct 21 ms 5260 KB Output is correct
19 Correct 21 ms 5360 KB Output is correct
20 Correct 21 ms 5260 KB Output is correct

Subtask #2
0 / 22.0

# 결과 실행 시간 메모리 Grader output
1 Correct 117 ms 5444 KB Output is correct
2 Correct 122 ms 5536 KB Output is correct
3 Correct 112 ms 5348 KB Output is correct
4 Correct 113 ms 5284 KB Output is correct
5 Correct 114 ms 5308 KB Output is correct
6 Correct 112 ms 5344 KB Output is correct
7 Correct 118 ms 5320 KB Output is correct
8 Correct 113 ms 5332 KB Output is correct
9 Correct 110 ms 5356 KB Output is correct
10 Correct 111 ms 5284 KB Output is correct
11 Correct 117 ms 5264 KB Output is correct
12 Correct 111 ms 5324 KB Output is correct
13 Correct 120 ms 5376 KB Output is correct
14 Correct 110 ms 5296 KB Output is correct
15 Correct 112 ms 5316 KB Output is correct
16 Correct 22 ms 5312 KB Output is correct
17 Correct 22 ms 5392 KB Output is correct
18 Correct 21 ms 5260 KB Output is correct
19 Correct 21 ms 5360 KB Output is correct
20 Correct 21 ms 5260 KB Output is correct
21 Execution timed out 2096 ms 18964 KB Time limit exceeded
22 Halted 0 ms 0 KB -

Subtask #3
0 / 27.0

# 결과 실행 시간 메모리 Grader output
1 Incorrect 427 ms 2656 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #4
0 / 42.0

# 결과 실행 시간 메모리 Grader output
1 Correct 117 ms 5444 KB Output is correct
2 Correct 122 ms 5536 KB Output is correct
3 Correct 112 ms 5348 KB Output is correct
4 Correct 113 ms 5284 KB Output is correct
5 Correct 114 ms 5308 KB Output is correct
6 Correct 112 ms 5344 KB Output is correct
7 Correct 118 ms 5320 KB Output is correct
8 Correct 113 ms 5332 KB Output is correct
9 Correct 110 ms 5356 KB Output is correct
10 Correct 111 ms 5284 KB Output is correct
11 Correct 117 ms 5264 KB Output is correct
12 Correct 111 ms 5324 KB Output is correct
13 Correct 120 ms 5376 KB Output is correct
14 Correct 110 ms 5296 KB Output is correct
15 Correct 112 ms 5316 KB Output is correct
16 Correct 22 ms 5312 KB Output is correct
17 Correct 22 ms 5392 KB Output is correct
18 Correct 21 ms 5260 KB Output is correct
19 Correct 21 ms 5360 KB Output is correct
20 Correct 21 ms 5260 KB Output is correct
21 Execution timed out 2096 ms 18964 KB Time limit exceeded
22 Halted 0 ms 0 KB -