제출 #1334924

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1334924		SmuggingSpun	Trains (BOI24_trains)	C++20	100 / 100	208 ms	119028 KiB

Main

#include<bits/stdc++.h>
#define taskname "C"
using namespace std;
typedef long long ll;
const int lim = 1e5 + 5;
const int mod = 1e9 + 7;
void add(int& a, int b){
  if((a += b) >= mod){
    a -= mod;
  }
}
void sub(int& a, int b){
  if((a -= b) < 0){
    a += mod;
  }
}
int n, d[lim], x[lim];
namespace sub12{
  void solve(){
    vector<int>dp(n + 1, 0);
    for(int i = dp[1] = 1; i <= n; i++){
      if(d[i] > 0){
        for(int j = i + d[i]; j <= n && x[i] > 0; j += d[i], x[i]--){
          add(dp[j], dp[i]);
        }
      }
    }
    cout << accumulate(dp.begin(), dp.end(), 0LL) % mod;
  }
}
namespace sub345{
  const int SIZE = 300;
  int dp[lim], f[SIZE][lim];
  void solve(){
    memset(dp, 0, sizeof(dp));
    memset(f, 0, sizeof(f));
    for(int i = dp[1] = 1; i <= n; i++){
      for(int j = min(SIZE - 1, i); j > 0; j--){
        add(f[j][i], f[j][i - j]);
        add(dp[i], f[j][i]);
      }
      if(d[i] > 0){
        if(d[i] >= SIZE){
          for(int j = i + d[i]; j <= n && x[i] > 0; j += d[i], x[i]--){
            add(dp[j], dp[i]);
          }
        }
        else if(i + d[i] <= n){
          add(f[d[i]][i + d[i]], dp[i]);
          if(i + ll(x[i] + 1) * d[i] <= n){
            sub(f[d[i]][i + (x[i] + 1) * d[i]], dp[i]);
          }
        }
      }
    }
    cout << accumulate(dp + 1, dp + n + 1, 0LL) % mod;
  }
}
int main(){
	ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
	if(fopen(taskname".inp", "r")){
		freopen(taskname".inp", "r", stdin);
	}
  cin >> n;
  for(int i = 1; i <= n; i++){
    cin >> d[i] >> x[i];
  }
  if(n <= 10000){
    sub12::solve();
  }
  else{
    sub345::solve();
  }
}

컴파일 시 표준 에러 (stderr) 메시지

Main.cpp: In function 'int main()':
Main.cpp:62:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   62 |                 freopen(taskname".inp", "r", stdin);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~

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