Submission #946367

#	Time	Username	Problem	Language	Result	Execution time	Memory
946367		hmm789	Fancy Fence (CEOI20_fancyfence)	C++14	12 / 100	1 ms	452 KiB

fancyfence

#include <bits/stdc++.h>
using namespace std;
#define int long long
#define INF 1000000000000000000
#define MOD 1000000007

struct node {
    int s, e, m, sm, mn;
    node *l, *r;
    node(int _s, int _e) {
        s = _s, e = _e, m = (s+e)/2, sm = mn = 0;
        if(s != e) {
            l = new node(s, m);
            r = new node(m+1, e);
        }
    }
    void update(int x, int val) {
        if(s == e) {sm = mn = val; return;}
        else if(x > m) r->update(x, val);
        else l->update(x, val);
        sm = (l->sm + r->sm) % MOD;
        mn = min(l->mn, r->mn);
    }
    int rsum(int x, int y) {
        if(x > y) return 0;
        if(x <= s && e <= y) return sm;
        else if(x > m) return r->rsum(x, y);
        else if(y <= m) return l->rsum(x, y);
        else return (l->rsum(x, y) + r->rsum(x, y)) % MOD;
    }
    int rmin(int x, int y) {
        if(x > y) return -INF;
        if(x <= s && e <= y) return mn;
        else if(x > m) return r->rmin(x, y);
        else if(y <= m) return l->rmin(x, y);
        else return min(l->rmin(x, y), r->rmin(x, y));
    }
} *rh, *rw;

int32_t main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    int n, ans = 0, sm = 0;
    cin >> n;
    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];
    stack<tuple<int, int, int>> s;
    for(int i = 0; i < n; i++) {
        int num = (h[i]+1)*h[i]/2 % MOD, num2 = (w[i]+1)*w[i]/2 % MOD;
        ans += num * num2 % MOD;
        ans %= MOD;
        int nnw = w[i], nv;
        while(s.size() && get<0>(s.top()) >= h[i]) {
            int nh, nw, val;
            tie(nh, nw, val) = s.top();
            s.pop();
            ans += w[i]*nw % MOD * num % MOD;
            ans %= MOD;
            sm -= val;
            nnw += nw;
        }
        ans += w[i]*sm % MOD;
        ans %= MOD;
        nv = h[i]*(h[i]+1)/2 * nnw % MOD;
        sm += nv;
        s.push({h[i], nnw, nv});
    }
    cout << ans;
}

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