Submission #1234988

#	Time	Username	Problem	Language	Result	Execution time	Memory
1234988		ThommyDB	Trains (BOI24_trains)	C++20	100 / 100	504 ms	296468 KiB

Main

#include<bits/stdc++.h>

using namespace std;
#define int long long

const int MOD = 1e9+7;

signed main(){
    int n;
    cin >> n;
    vector<int> d(n+1), x(n+1);
    for(int i = 0; i < n; i++){
        cin >> d[i] >> x[i];
    }
    vector<int> ans(n, 0);
    ans[0]=1;
    int totalans = 0;
    vector<vector<int>> pref(n+5, vector<int>(370));
    for(int i = 0; i < n; i++){
        for (int j = 0; j <= 360; j++) {
            if (i-j >= 0)pref[i][j]+=pref[i-j][j]; 
            pref[i][j]%= MOD;
            ans[i] +=pref[i][j];
            ans[i] %= MOD;
        }
        if(d[i]>360){
            for(int j = 1; j <= x[i]; j++){
                int k = i+d[i]*j;
                if(k>=n)break;
                ans[k]+=ans[i];
                ans[k]%=MOD;
            }
        }
        else{
            pref[i][d[i]]+= ans[i];
            pref[i][d[i]] %= MOD;
            int r = min(i+(x[i]+1)*d[i],n);
            pref[r][d[i]] +=MOD-ans[i]; 
            pref[r][d[i]] %= MOD; 
        }
        totalans+=ans[i];
        totalans%=MOD;
    }
    cout << totalans << "\n";
}

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