Submission #1235823

#	Time	Username	Problem	Language	Result	Execution time	Memory
1235823		Ska	Modsum (NOI12_modsum)	C++20	25 / 25	124 ms	456 KiB

modsum

#include <bits/stdc++.h>
using namespace std;
int n;
pair<int, int> f[1005];
int backtrack(int i, int sum){
    sum%=5;
    int ans=0;
    if(i==n){
        return ((sum*sum+2)*sum*sum)%5+1;
    }
    for(int j=f[i].first; j<=f[i].second; j++){
        ans+=backtrack(i+1, sum+j);
    }
    return ans;
}
int main(){
    cin>>n;
    for(int i=0; i<n; i++){
        cin>>f[i].first>>f[i].second;
    }
    cout<<backtrack(0, 0);
    return 0;
}

• Subtask 1: 5 / 5
• Subtask 2: 5 / 5
• Subtask 3: 5 / 5
• Subtask 4: 5 / 5
• Subtask 5: 5 / 5