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Submission #827540

# Submission time Handle Problem Language Result Execution time Memory
827540 2023-08-16T14:30:24 Z PagodePaiva Fancy Fence (CEOI20_fancyfence) C++17
100 / 100
 262 ms 8992 KB 
#include<bits/stdc++.h>
#define pii pair <int, int>
#define fr first
#define sc second
#define N 100010
#define inf 1e18
#define int long long

using namespace std;

int n;
int h[N], w[N];
int pref[N];
int mod = 1e9+7;

struct Segtree{
    pair <int,int> tree[4*N];

    pair <int,int> join(pii a, pii b){
        if(a.fr < b.fr) return a;
        if(a.fr > b.fr) return b;
        if(a.sc < b.sc) return a;
        return b;
    }

    void build(int l, int r, int node){
        if(l == r){
            tree[node] = {h[l], l};
            return;
        }

        int mid = (l+r)/2;

        build(l, mid, 2*node);
        build(mid+1, r, 2*node+1);

        tree[node] = join(tree[2*node], tree[2*node+1]);

        return;
    }

    pair <int, int> query(int l, int r, int tl, int tr, int node){
        if(tl > r or tr < l) return {inf, inf};
        if(l <= tl and tr <= r) return tree[node];

        int mid = (tl+tr)/2;

        return join(query(l, r, tl, mid, 2*node), query(l, r, mid+1, tr, 2*node+1));
    }
} seg;

long long binpow(long long a, long long b, long long m) {
    a %= m;
    long long res = 1;
    while (b > 0) {
        if (b & (1ll))
            res = res * a % m;
        a = a * a % m;
        b >>= (1ll);
    }
    return res;
}

int query(int l, int r, int minant){
    int c = pref[r] - pref[l-1];
    c %= mod;
    c += mod;
    c %= mod;
    int a = seg.query(l, r, 1, n, 1).fr;
    a %= mod;

    int res = (c-1)*(a-1);
    res %= mod;
    res *= c;
    res %= mod;
    res *= a;
    res %= mod;
    res *= binpow(4, mod-2, mod);
    res %= mod;
    int aux = (a+c-2)*a;
    aux %= mod;
    aux *= c;
    aux %= mod;
    aux *= binpow(2, mod-2, mod);
    aux %= mod;
    res += aux;
    res %= mod; 
    res += ((a*c) % mod);
    res %= mod;

    a = minant % mod;    

    int res2 = (c-1)*(a-1);
    res2 %= mod;
    res2 *= c;
    res2 %= mod;
    res2 *= a;
    res2 %= mod;
    res2 *= binpow(4, mod-2, mod);
    res2 %= mod;
    aux = (a+c-2)*a;
    aux %= mod;
    aux *= c;
    aux %= mod;
    aux *= binpow(2, mod-2, mod);
    aux %= mod;
    res2 += aux;
    res2 %= mod; 
    res2 += ((a*c) % mod);
    res2 %= mod;
    
    // cout << res2 << "\n";

    res = res-res2;

    res %= mod;
    res += mod;
    res %= mod;

    // cout << l << ' ' << r << ' ' << minant << ": " <<  res << "\n";

    return res % mod;
}

int32_t main(){
    cin >> n;

    for(int i = 1;i <= n;i++){
        cin >> h[i];
    }

    for(int i = 1;i <= n;i++){
        cin >> w[i];
    }

    seg.build(1, n, 1);

    queue <array <int,4>> q;
    q.push({1, n, 0, 0});

    for(int i = 1;i <= n;i++){
        pref[i] = pref[i-1] + w[i];
        pref[i] %= mod;
    }

    int res = 0;

    while(!q.empty()){
        auto [l, r, minant, aux] = q.front();
        q.pop();

        if(aux == 0){
            res += query(l, r, minant); res %= mod;
            auto [minn, pos] = seg.query(l, r, 1, n, 1);

            if(pos != l) q.push({l, pos-1, minn, 0});
            if(pos != r) q.push({pos+1, r, minn, 1});
        }

        else{
            auto [minn, pos] = seg.query(l, r, 1, n, 1);
            if(minant == minn){
                if(pos != l) q.push({l, pos-1, minn, 0});
                if(pos != r) q.push({pos+1, r, minn, 1});       
            }
            else{
                q.push({l, r, minant, 0});
            }
        }
    }

    // cout << binpow(4, mod-1, mod); 

    cout << res << '\n';

    return 0;
}

Subtask #1
0.0 / 0.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 3 ms 380 KB Output is correct

Subtask #2
12.0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 1 ms 304 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct

Subtask #3
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 224 KB Output is correct
2 Correct 1 ms 340 KB Output is correct
3 Correct 47 ms 3468 KB Output is correct
4 Correct 94 ms 6664 KB Output is correct
5 Correct 93 ms 6740 KB Output is correct
6 Correct 70 ms 6640 KB Output is correct

Subtask #4
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 7 ms 980 KB Output is correct
3 Correct 35 ms 3532 KB Output is correct
4 Correct 67 ms 6740 KB Output is correct
5 Correct 69 ms 6696 KB Output is correct
6 Correct 0 ms 212 KB Output is correct

Subtask #5
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 1 ms 340 KB Output is correct
3 Correct 7 ms 980 KB Output is correct
4 Correct 35 ms 3524 KB Output is correct
5 Correct 68 ms 6644 KB Output is correct
6 Correct 70 ms 6688 KB Output is correct
7 Correct 4 ms 340 KB Output is correct
8 Correct 24 ms 1264 KB Output is correct
9 Correct 73 ms 4536 KB Output is correct
10 Correct 245 ms 8572 KB Output is correct
11 Correct 247 ms 8676 KB Output is correct
12 Correct 0 ms 212 KB Output is correct

Subtask #6
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 3 ms 380 KB Output is correct
3 Correct 0 ms 308 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 0 ms 212 KB Output is correct
6 Correct 0 ms 212 KB Output is correct
7 Correct 1 ms 212 KB Output is correct
8 Correct 1 ms 316 KB Output is correct
9 Correct 1 ms 312 KB Output is correct
10 Correct 3 ms 320 KB Output is correct
11 Correct 1 ms 340 KB Output is correct
12 Correct 2 ms 340 KB Output is correct
13 Correct 3 ms 340 KB Output is correct
14 Correct 3 ms 340 KB Output is correct
15 Correct 3 ms 340 KB Output is correct
16 Correct 0 ms 212 KB Output is correct

Subtask #7
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 3 ms 380 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 3 ms 320 KB Output is correct
5 Correct 0 ms 312 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Correct 1 ms 304 KB Output is correct
8 Correct 0 ms 212 KB Output is correct
9 Correct 1 ms 212 KB Output is correct
10 Correct 1 ms 340 KB Output is correct
11 Correct 55 ms 4116 KB Output is correct
12 Correct 78 ms 7908 KB Output is correct
13 Correct 93 ms 8008 KB Output is correct
14 Correct 71 ms 7904 KB Output is correct
15 Correct 1 ms 340 KB Output is correct
16 Correct 9 ms 1236 KB Output is correct
17 Correct 34 ms 4504 KB Output is correct
18 Correct 69 ms 8620 KB Output is correct
19 Correct 71 ms 8784 KB Output is correct
20 Correct 3 ms 340 KB Output is correct
21 Correct 24 ms 1248 KB Output is correct
22 Correct 71 ms 4504 KB Output is correct
23 Correct 241 ms 8468 KB Output is correct
24 Correct 245 ms 8568 KB Output is correct
25 Correct 1 ms 212 KB Output is correct
26 Correct 2 ms 340 KB Output is correct
27 Correct 3 ms 340 KB Output is correct
28 Correct 3 ms 340 KB Output is correct
29 Correct 3 ms 340 KB Output is correct
30 Correct 25 ms 1296 KB Output is correct
31 Correct 26 ms 1276 KB Output is correct
32 Correct 118 ms 4412 KB Output is correct
33 Correct 127 ms 4528 KB Output is correct
34 Correct 254 ms 8792 KB Output is correct
35 Correct 238 ms 8500 KB Output is correct
36 Correct 257 ms 8992 KB Output is correct
37 Correct 259 ms 8964 KB Output is correct
38 Correct 0 ms 212 KB Output is correct
39 Correct 251 ms 8860 KB Output is correct
40 Correct 262 ms 8744 KB Output is correct
41 Correct 255 ms 8692 KB Output is correct
42 Correct 240 ms 8664 KB Output is correct