Submission #963036

#	Time	Username	Problem	Language	Result	Execution time	Memory
963036		anton	Fancy Fence (CEOI20_fancyfence)	C++17	0 / 100	1 ms	504 KiB

fancyfence

#include<bits/stdc++.h>

using namespace std;
#define int long long
#define pii pair<int,int>

const int MAX_N = 1e5+1;
const int mod =1e9+7;

int h[MAX_N];
int w[MAX_N];

int nbp(int u){
    return (u*(u+1LL)/2LL)%mod;
}
signed main(){
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    int n; 
    cin>>n;
    int sw = 0;
    for(int i = 0; i<n; i++){
        cin>>h[i];
    }
    for(int i = 0; i<n; i++){
        cin>>w[i];
        sw = (sw+w[i])%mod;
    }
    h[n] = 0;

    int res= 0;
    
    res= nbp(sw);

    int prev_end = 0;
    int pref= 0;
    for(int i = 0; i<=n; i++){
        if(h[i] <= 1){
            res = (res+ 2*nbp(pref-prev_end))%mod;
            prev_end = pref+w[i];
        }
        pref += w[i];
    }
    cout<<res<<endl;
}

• Subtask 1: 0 / 0
• Subtask 2: 0 / 12
• Subtask 3: 0 / 13
• Subtask 4: 0 / 15
• Subtask 5: 0 / 15
• Subtask 6: 0 / 18
• Subtask 7: 0 / 27