Submission #1033596

#	Time	Username	Problem	Language	Result	Execution time	Memory
1033596		trucmai	Trains (BOI24_trains)	C++17	0 / 100	6 ms	4700 KiB

Main

#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;
typedef long double ld;
#define pb push_back
#define pf push_front
#define fi first
#define se second
const ll mod = 1e9+7, mxn = 1e5+7, block = 320;
ll dp[mxn], d[mxn], x[mxn], n;
signed main()
{
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    freopen("test.inp","r",stdin); freopen("test.out","w",stdout); freopen("test.err","w",stderr);
    ll n; cin >> n; dp[1] = 1;
    for (ll i = 1; i <= n; i++) 
    {
        cin >> d[i] >> x[i];
        if (d[i] && x[i] <= block)
        {
            for (ll j = i+d[i]; j <= min(n, i+x[i]*d[i]); j += d[i]) 
            {
                dp[j] += dp[i];
                dp[j] %= mod;
            }
        }
    }
    vector<pair<ll,pair<ll,ll>>> v;
    for (ll i = 1; i <= n; i++)
    {
        for (pair<ll,pair<ll,ll>> j : v) if ((i-j.fi)%j.se.fi == 0 && (i-j.fi)/j.se.fi <= j.se.se)
        {
            dp[i] += dp[j.fi];
            dp[i] %= mod;
        }
        if (d[i] && x[i] > block) v.pb({i,{d[i],x[i]}}); 
    }
    ll ans = 0;
    for (ll i = 1; i <= n; i++) 
    {
        ans += dp[i];
        ans %= mod;
    }
    cout << ans;
}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:14:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   14 |     freopen("test.inp","r",stdin); freopen("test.out","w",stdout); freopen("test.err","w",stderr);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
Main.cpp:14:43: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   14 |     freopen("test.inp","r",stdin); freopen("test.out","w",stdout); freopen("test.err","w",stderr);
      |                                    ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:14:75: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   14 |     freopen("test.inp","r",stdin); freopen("test.out","w",stdout); freopen("test.err","w",stderr);
      |                                                                    ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

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