Submission #1033578

#	Time	Username	Problem	Language	Result	Execution time	Memory
1033578		BuiDucManh123	Trains (BOI24_trains)	C++14	21 / 100	2062 ms	3208 KiB

Main

#include <bits/stdc++.h>
#define fi first
#define se second
#define ll long long
#define ull unsigned long long
#define pii pair<int, int>
#define pll pair<ll, ll>
#define pb push_back
#define taskname ""
using namespace std;
const int mod=1e9+7;
ll n,i,a[100009],d[100009],x[100009],bit[100009],f[100009],j,ans;
bool check;
void update(int id,int val){
    while(id<=n){
        bit[id]+=val;
        bit[id]%=mod;
        id+=id&-id;
    }
}
ll get(int id){
    ll res=0;
    while(id){
        res+=bit[id];
        res%=mod;
        id-=id&-id;
    }return res;
}
int main() {
	if (fopen(taskname".inp","r")) {
		freopen(taskname".inp","r",stdin);
		freopen(taskname".out","w",stdout);
	}
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
    cin>>n;check=true;
    for(i=1;i<=n;i++){
        cin>>d[i]>>x[i];
        if(d[i]!=1) check=false;
    }
    if(check==false){
        f[1]=1;
        for(i=1;i<=n;i++){
            for(j=1;j<i;j++){
                if(d[j]!=0&&(i-j)%d[j]==0&&i<=j+d[j]*x[j]){
                    f[i]+=f[j];
                    f[i]%=mod;
                }
            }
        }ans=0;
        for(i=1;i<=n;i++) ans+=f[i],ans%=mod;
        cout<<ans;
    }else{
        update(1,1);
        update(2,-1);
        for(i=1;i<=n;i++){
            j=get(i);
            update(i+1,j);
            update(i+x[i]+1,-j);
        }
        for(i=1;i<=n;i++){
            ans+=get(i);
            ans%=mod;
        }cout<<ans;
    }
	return 0;
}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:31:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   31 |   freopen(taskname".inp","r",stdin);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:32:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   32 |   freopen(taskname".out","w",stdout);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

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