oj.uz

Submission #679241

# Submission time Handle Problem Language Result Execution time Memory
679241 2023-01-07T21:06:56 Z stevancv Boat (APIO16_boat) C++14
27 / 100
 1373 ms 3760 KB 
#include <bits/stdc++.h>
#define ll long long
#define ld long double
#define sp ' '
#define en '\n'
#define smin(a, b) a = min(a, b)
#define smax(a, b) a = max(a, b)
#define sadd(a, b) a = Add(a, b)
#define smul(a, b) a = Mul(a, b)
using namespace std;
const int N = 500 + 2;
const int mod = 1e9 + 7;
int fak[N], inv[N];
int Add(int a, int b) {
    a += b;
    while (a >= mod) a -= mod;
    while (a < 0) a += mod;
    return a;
}
int Mul(int a, int b) {
    ll c = a; c *= b; c %= mod;
    return c;
}
int Exp(int a, int b) {
    int ans = 1;
    while (b > 0) {
        if (b & 1) smul(ans, a);
        smul(a, a);
        b >>= 1;
    }
    return ans;
}
int koef[2 * N][N], dp[2 * N][N];
bool pos[2 * N][N];
int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    fak[0] = inv[0] = 1;
    for (int i = 1; i < N; i++) {
        fak[i] = Mul(fak[i - 1], i);
        inv[i] = Exp(fak[i], mod - 2);
    }
    int n; cin >> n;
    vector<int> a(n), b(n), all;
    all.push_back(-1);
    for (int i = 0; i < n; i++) {
        cin >> a[i] >> b[i];
        a[i] -= 1;
        all.push_back(a[i]);
        all.push_back(b[i]);
    }
    sort(all.begin(), all.end());
    all.erase(unique(all.begin(), all.end()), all.end());
    int x = all.size();
    for (int i = 1; i < x; i++) {
        int l = all[i] - all[i - 1];
        for (int j = 1; j <= n; j++) {
            int p = l, q = 1;
            for (int k = 1; k <= j; k++) {
                sadd(koef[i][j], Mul(Mul(p, inv[k]), Mul(q, inv[k - 1])));
                smul(p, l - k);
                smul(q, j - k);
            }
        }
    }
    for (int i = 0; i < n; i++) {
        a[i] = lower_bound(all.begin(), all.end(), a[i]) - all.begin();
        b[i] = lower_bound(all.begin(), all.end(), b[i]) - all.begin();
    }
    for (int j = 0; j < x; j++) dp[0][j] = 1;
    for (int i = 0; i < n; i++) {
        for (int j = a[i] + 1; j <= b[i]; j++) {
            int y = 1;
            for (int k = i; k >= 0; k--) {
                sadd(dp[i + 1][j], Mul(dp[k][j - 1], koef[j][y]));
                if (pos[j][k - 1]) y += 1;
            }
            pos[j][i] = 1;
        }
        for (int j = 1; j < x; j++) sadd(dp[i + 1][j], dp[i + 1][j - 1]);
    }
    int ans = 0;
    for (int i = 1; i <= n; i++) sadd(ans, dp[i][x - 1]);
    cout << ans << en;
    return 0;
}

Subtask #1
0 / 9.0

# Verdict Execution time Memory Grader output
1 Incorrect 1373 ms 3760 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #2
0 / 22.0

# Verdict Execution time Memory Grader output
1 Incorrect 1373 ms 3760 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #3
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 18 ms 1000 KB Output is correct
2 Correct 19 ms 952 KB Output is correct
3 Correct 22 ms 968 KB Output is correct
4 Correct 18 ms 952 KB Output is correct
5 Correct 19 ms 972 KB Output is correct
6 Correct 21 ms 972 KB Output is correct
7 Correct 20 ms 952 KB Output is correct
8 Correct 19 ms 1016 KB Output is correct
9 Correct 22 ms 924 KB Output is correct
10 Correct 19 ms 992 KB Output is correct
11 Correct 18 ms 1032 KB Output is correct
12 Correct 17 ms 916 KB Output is correct
13 Correct 17 ms 972 KB Output is correct
14 Correct 18 ms 980 KB Output is correct
15 Correct 17 ms 980 KB Output is correct
16 Correct 10 ms 724 KB Output is correct
17 Correct 9 ms 796 KB Output is correct
18 Correct 11 ms 712 KB Output is correct
19 Correct 12 ms 724 KB Output is correct
20 Correct 10 ms 724 KB Output is correct

Subtask #4
0 / 42.0

# Verdict Execution time Memory Grader output
1 Incorrect 1373 ms 3760 KB Output isn't correct
2 Halted 0 ms 0 KB -