Submission #1097167

#	Time	Username	Problem	Language	Result	Execution time	Memory
1097167		manhlinh1501	Trains (BOI24_trains)	C++17	21 / 100	2091 ms	3164 KiB

Main

#include<bits/stdc++.h>
using namespace std;
using i64 = long long;
const int MAXN = 1e5 + 5;
using pii = pair<int, int>;
const i64 MOD = 1e9 + 7;
const int BLOCK = 370;

int N;
pii a[MAXN];
i64 dp[MAXN];
int cnt[BLOCK][MAXN];

namespace subtask {
    void solution() {
        dp[1] = 1;
        for(int i = 1; i <= N; i++) {
            if(a[i].first == 0) continue;

            for(int j = 1; j <= a[i].second and i + j * a[i].first <= N; j++) {
                if(i + j * a[i].first <= N) {
                    dp[i + j * a[i].first] += dp[i];
                    dp[i + j * a[i].first] %= MOD;
                }
            }
        }
        i64 ans = 0;
        for(int i = 1; i <= N; i++) {
            ans += dp[i];
            ans %= MOD;
        }
        cout << ans << "\n";
    }
}

signed main() {
#define TASK ""
    if(fopen(TASK".inp", "r")) {
        freopen(TASK".inp", "r", stdin);
        freopen(TASK".out", "w", stdout);
    }
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    cin >> N;

    for(int i = 1; i <= N; i++) cin >> a[i].first >> a[i].second;

    subtask::solution();
}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:39:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   39 |         freopen(TASK".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:40:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   40 |         freopen(TASK".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 8 / 8
• Subtask 2: 13 / 13
• Subtask 3: 0 / 16
• Subtask 4: 0 / 34
• Subtask 5: 0 / 29