Submission #958908

#	Time	Username	Problem	Language	Result	Execution time	Memory
958908		TAhmed33	Fancy Fence (CEOI20_fancyfence)	C++98	30 / 100	1100 ms	1428 KiB

fancyfence

#include <bits/stdc++.h>
using namespace std;
const int MOD = 1e9 + 7;
const int TWOINV = 5e8 + 4;
const int MAXN = 1e5 + 25;
int add (int a, int b) {
    a += b; if (a >= MOD) a -= MOD;
    return a;
}
int sub (int a, int b) {
    a -= b; if (a < 0) a += MOD;
    return a;
}
int mul (int a, int b) {
    return (a * 1ll * b) % MOD;
}
int h[MAXN], w[MAXN], n;
int main () {
    ios::sync_with_stdio(0); cin.tie(0);
    cin >> n;
    for (int i = 1; i <= n; i++) cin >> h[i];
    for (int i = 1; i <= n; i++) cin >> w[i];
    int ans = 0;
    for (int i = 1; i <= n; i++) {
        int x = w[i], y = h[i];
        x = mul(x, mul(x + 1, TWOINV));
        y = mul(y, mul(y + 1, TWOINV));
        ans = add(ans, mul(x, y));
    }
    for (int i = 1; i <= n; i++) {
        for (int j = i + 1; j <= n; j++) {
            int x = *min_element(h + i, h + j + 1);
            x = mul(x, mul(x + 1, TWOINV));
            int y = mul(w[i], w[j]);
            ans = add(ans, mul(x, y));
        }
    }
    cout << ans << '\n';
}

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