Submission #922044

#	Time	Username	Problem	Language	Result	Execution time	Memory
922044		Alebn	Fancy Fence (CEOI20_fancyfence)	C++14	0 / 100	1045 ms	348 KiB

fancyfence

#include <bits/stdc++.h>
#define int long long
 
using namespace std;
 
const int MOD = 1e9+7, INV = 250000002;
 
int mod(int n) {
    return (n + 3 * MOD) % MOD;
}
int f(int n, int m) {
    n = mod(n), m = mod(m);
    return n * m % MOD * (n + 1) % MOD * (m + 1) % MOD * INV % MOD;
}
 
signed main() {
    //input and sum
    int n;
    cin >> n;
    vector<int> h(n), w(n);
    for(int i = 0; i < n; i++) cin >> h[i];
    for(int i = 0; i < n; i++) cin >> w[i];
    //linearily go over and compute result
    int res = 0, temp;
    for(int i = 0; i < n; i++) {
        int minH = h[i], sumW = w[i];
        res = mod(res + f(minH, sumW));
        for(int j = i+1; j < n; j++) {
            minH = min(minH, h[i]), sumW = mod(sumW + w[j]);
            temp = f(minH, sumW);
            temp -= mod(f(minH, sumW - w[j]) + f(minH, sumW - w[i]));
            temp = mod(temp);
            temp += f(minH, sumW - w[i] - w[j]);
            res = mod(res + temp);
        }
    }
    cout << res << "\n";
}

• 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