Submission #556507

#	Time	Username	Problem	Language	Result	Execution time	Memory
556507		InternetPerson10	Boat (APIO16_boat)	C++17	9 / 100	19 ms	17092 KiB

boat

#include <bits/stdc++.h>
typedef long long ll;

using namespace std;

const ll MOD = 1e9 + 7;
ll BIG = 2100002;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    int n;
    cin >> n;
    vector<ll> a(n), b(n);
    vector<unsigned int> nums;
    nums.resize(BIG);
    nums[BIG - 1] = 3;
    map<int, int> m;
    bool st1 = true;
    for(int i = 0; i < n; i++) {
        cin >> a[i] >> b[i];
        m[a[i]]++;
        m[b[i]]--;
        if(a[i] != b[i]) st1 = false;
    }
    int x = 0;
    ll mi = 0;
    for(auto p : m) {
        if(x == 0) {
            mi += p.first - 1;
        }
        for(int i = 0; i < n; i++) {
            if(a[i] == p.first) a[i] -= mi;
            if(b[i] == p.first) b[i] -= mi;
        }
        x += p.second;
        if(x == 0) {
            mi -= p.first;
        }
    }
    if(st1) {
        vector<ll> sums(n, 1);
        for(int i = 1; i < n; i++) {
            for(int j = 0; j < i; j++) {
                if(a[j] < a[i]) sums[i] += sums[j];
                sums[i] %= MOD;
            }
        }
        ll ans = 0;
        for(int i = 0; i < n; i++) ans += sums[i];
        cout << ans % MOD << '\n';
        return 0;
    }
    ll ma = 0;
    for(int i = 0; i < n; i++) {
        ma = max(ma, a[i]);
        ma = max(ma, b[i]);
    }
    nums[0] = 1;
    for(int i = 0; i < n; i++) {
        ll g = 0;
        for(int j = 0; j < a[i]; j++) {
            g += nums[j];
            g %= MOD;
        }
        for(int j = a[i]; j <= b[i]; j++) {
            ll x = g;
            g += nums[j];
            nums[j] += x;
            nums[j] += MOD;
            nums[j] %= MOD;
            g %= MOD;
        }
    }
    ll ans = 0;
    for(int i = 1; i < BIG; i++) {
        ans += nums[i];
        ans %= MOD;
    }
    cout << ans << '\n';
}

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