Submission #942373

#	Time	Username	Problem	Language	Result	Execution time	Memory
942373		batsukh2006	Fancy Fence (CEOI20_fancyfence)	C++17	15 / 100	23 ms	3676 KiB

fancyfence

#include<iostream>
#include<stdio.h>
#include<math.h>
#include<map>
#include<string>
#include<algorithm>
#include<vector>
#include<string.h>
#include<utility>
#include<set>
#include<cmath>
#include<queue>
#include<deque>
#include<functional>
#include<stack>
#include<limits.h>
#include<iomanip>
#include<unordered_map> 
 
using namespace std;
 
#define MOD 1000000007
#define int long long
#define endl '\n'
int cal(int a, int b){
    int f=(a*(a+1))%MOD*((MOD+1)/2)%MOD;
    int s=(b*(b+1))%MOD*((MOD+1)/2)%MOD;
    return (f*s)%MOD;
}
void solve(){
    int n; cin>>n;
    vector<int> h(n+1),w(n+1);
    for(int i=1; i<=n; i++) cin>>h[i];
    for(int i=1; i<=n; i++) cin>>w[i];
    int ans=0,sum=0;
    for(int i=1; i<=n; i++){
        if(h[i]>h[i-1]) sum=w[i];
        else sum=(sum+w[i])%MOD;
        ans=(ans+cal(sum,h[i]))%MOD;
        ans=(ans-cal(sum-w[i],h[i])+MOD)%MOD;
    }
    sum=0;
    int cur=0;
    for(int i=n; i>=1; i--){
        if(h[i]>h[i+1]) sum=w[i];
        else sum=(sum+w[i])%MOD;
        if(h[i]==h[i+1]) cur=(cur+w[i])%MOD;
        else cur=w[i];
        if(sum!=cur){
            ans=(ans+cal(sum,h[i]))%MOD;
            ans=(ans-cal(cur,h[i])+MOD)%MOD;
            ans=(ans-cal(sum-w[i],h[i])+MOD)%MOD;
        }
    }
    cout<<ans;
}
signed main(){
	// freopen("hps.in", "r", stdin);
	// freopen("hps.out", "w", stdout);
	ios::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	
	int t=1;
	// cin>>t;
	while(t--){
		solve();
		cout<<endl;
	}
	return 0;
}

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