제출 #109122

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
109122		fedoseevtimofey	Boat (APIO16_boat)	C++14	9 / 100	9 ms	3584 KiB

boat

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef long double ld;

const int md = 1e9 + 7;

void add(int &a, int b) {
    a += b;
    if (a >= md) a -= md;
}

int sub(int a, int b) {
    a -= b;
    if (a < 0) a += md;
    return a;
}

int mul(int a, int b) {
    return ((ll)a * b) % md;
}

int main() {
    ios_base::sync_with_stdio(false); cin.tie(0); cout.setf(ios::fixed); cout.precision(20);
    #ifdef LOCAL
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
    #endif
    int n;
    cin >> n;
    vector <int> a(n), b(n);
    for (int i = 0; i < n; ++i) cin >> a[i] >> b[i];
    vector <int> c;
    for (int i = 0; i < n; ++i) {
        c.push_back(a[i]); 
        c.push_back(b[i]);
        c.push_back(a[i] - 1);
        c.push_back(b[i] - 1);
    }
    sort(c.begin(), c.end());
    c.resize(unique(c.begin(), c.end()) - c.begin());
    for (int i = 0; i < n; ++i) {
        a[i] = lower_bound(c.begin(), c.end(), a[i]) - c.begin();
        b[i] = lower_bound(c.begin(), c.end(), b[i]) - c.begin();
    }
    int m = c.size();
    vector <vector <int>> dp(n + 1, vector <int> (m + 1));
    for (int j = 0; j <= m; ++j) dp[0][j] = 1;

    for (int i = 1; i <= n; ++i) {
        int l = a[i - 1];
        int r = b[i - 1];
        dp[i][0] = dp[i - 1][0];
        for (int j = 1; j <= m; ++j) {
            add(dp[i][j], dp[i][j - 1]);
            add(dp[i][j], sub(dp[i - 1][j], dp[i - 1][j - 1]));
            if (l <= j && j <= r) {
                add(dp[i][j], mul(sub(c[j], c[j - 1]), dp[i - 1][j - 1]));
            }
        }
    }
    cout << sub(dp[n][m], 1) << '\n';
}

• Subtask 1: 9 / 9
• Subtask 2: 0 / 22
• Subtask 3: 0 / 27
• Subtask 4: 0 / 42