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Submission #447085

# Submission time Handle Problem Language Result Execution time Memory
447085 2021-07-24T12:47:21 Z Yahli Fancy Fence (CEOI20_fancyfence) C++14
100 / 100
 115 ms 7316 KB 
#include <bits/stdc++.h>
#define int long long

using namespace std; 
using pi = pair<int, int>; 

const int mod = 1e9+7; 
const int inv4 = 25e7+2; 

int calc(int a, int b){
    a %= mod; b %= mod; 
    return ((a*(a+1)%mod)*(b*(b+1)%mod)%mod)*inv4%mod;
}

int32_t main(){
    int n; cin >> n;
    vector<pi> data(n); 
    for (int i = 0; i < n; ++i) cin >> data[i].first; 
    for (int i = 0; i < n; ++i) cin >> data[i].second; 

    //the stack trick
    stack<int> st;
    vector<int> left(n), right(n), ind; 

    for (int i = 0; i < n; ++i){
        while (!st.empty() && data[st.top()].first > data[i].first) st.pop(); 
        if (st.empty() || data[st.top()].first != data[i].first) ind.push_back(i); 
        left[i] = (st.empty() ? -1 : st.top()); 
        st.push(i); 
    }
    st = stack<int>(); 
    for (int i = n-1; i >= 0; --i){
        while (!st.empty() && data[st.top()].first >= data[i].first) st.pop(); 
        right[i] = (st.empty() ? n : st.top());  
        st.push(i); 
    }

    //prefix sums (width)
    vector<int> prefix(n+1); 
    prefix[0] = 0; 
    for (int i = 1; i <= n; ++i) prefix[i] = prefix[i-1] + data[i-1].second % mod; 

    //calculate the rectangles
    int res = 0; 
    
    for (int i : ind){
        int first = left[i] + 1, last = right[i] - 1; 
        int w = (prefix[last+1] - prefix[first] + mod) % mod, f = 0; 

        if (first != 0) f = max(f, data[first-1].first); 
        if (last != n-1) f = max(f, data[last+1].first); 

        res = (calc(data[i].first, w) - calc(f, w) + mod + res) % mod; 
    }

    cout << res;
}

Subtask #1
0.0 / 0.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 2 ms 332 KB Output is correct

Subtask #2
12.0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 204 KB Output is correct
2 Correct 1 ms 204 KB Output is correct
3 Correct 0 ms 204 KB Output is correct
4 Correct 1 ms 204 KB Output is correct
5 Correct 0 ms 204 KB Output is correct

Subtask #3
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 204 KB Output is correct
2 Correct 1 ms 332 KB Output is correct
3 Correct 33 ms 2488 KB Output is correct
4 Correct 63 ms 4932 KB Output is correct
5 Correct 67 ms 4664 KB Output is correct
6 Correct 64 ms 4412 KB Output is correct

Subtask #4
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 332 KB Output is correct
2 Correct 9 ms 716 KB Output is correct
3 Correct 44 ms 2232 KB Output is correct
4 Correct 94 ms 4152 KB Output is correct
5 Correct 91 ms 4152 KB Output is correct
6 Correct 0 ms 204 KB Output is correct

Subtask #5
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 204 KB Output is correct
2 Correct 1 ms 332 KB Output is correct
3 Correct 9 ms 712 KB Output is correct
4 Correct 55 ms 2216 KB Output is correct
5 Correct 115 ms 4152 KB Output is correct
6 Correct 93 ms 4148 KB Output is correct
7 Correct 1 ms 332 KB Output is correct
8 Correct 12 ms 972 KB Output is correct
9 Correct 48 ms 3360 KB Output is correct
10 Correct 100 ms 6828 KB Output is correct
11 Correct 105 ms 6936 KB Output is correct
12 Correct 1 ms 204 KB Output is correct

Subtask #6
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 204 KB Output is correct
2 Correct 1 ms 332 KB Output is correct
3 Correct 0 ms 204 KB Output is correct
4 Correct 0 ms 204 KB Output is correct
5 Correct 0 ms 204 KB Output is correct
6 Correct 0 ms 204 KB Output is correct
7 Correct 0 ms 204 KB Output is correct
8 Correct 1 ms 332 KB Output is correct
9 Correct 1 ms 332 KB Output is correct
10 Correct 1 ms 332 KB Output is correct
11 Correct 1 ms 204 KB Output is correct
12 Correct 1 ms 204 KB Output is correct
13 Correct 1 ms 332 KB Output is correct
14 Correct 1 ms 332 KB Output is correct
15 Correct 1 ms 332 KB Output is correct
16 Correct 0 ms 204 KB Output is correct

Subtask #7
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 2 ms 332 KB Output is correct
3 Correct 1 ms 204 KB Output is correct
4 Correct 1 ms 332 KB Output is correct
5 Correct 0 ms 204 KB Output is correct
6 Correct 0 ms 204 KB Output is correct
7 Correct 0 ms 204 KB Output is correct
8 Correct 0 ms 204 KB Output is correct
9 Correct 0 ms 204 KB Output is correct
10 Correct 1 ms 332 KB Output is correct
11 Correct 33 ms 2484 KB Output is correct
12 Correct 84 ms 4932 KB Output is correct
13 Correct 84 ms 4660 KB Output is correct
14 Correct 80 ms 4420 KB Output is correct
15 Correct 1 ms 332 KB Output is correct
16 Correct 9 ms 720 KB Output is correct
17 Correct 44 ms 2232 KB Output is correct
18 Correct 90 ms 4160 KB Output is correct
19 Correct 92 ms 4148 KB Output is correct
20 Correct 1 ms 332 KB Output is correct
21 Correct 10 ms 972 KB Output is correct
22 Correct 47 ms 3344 KB Output is correct
23 Correct 90 ms 6816 KB Output is correct
24 Correct 94 ms 6940 KB Output is correct
25 Correct 1 ms 204 KB Output is correct
26 Correct 1 ms 332 KB Output is correct
27 Correct 1 ms 332 KB Output is correct
28 Correct 1 ms 332 KB Output is correct
29 Correct 1 ms 332 KB Output is correct
30 Correct 10 ms 916 KB Output is correct
31 Correct 10 ms 952 KB Output is correct
32 Correct 50 ms 3608 KB Output is correct
33 Correct 49 ms 3644 KB Output is correct
34 Correct 89 ms 6824 KB Output is correct
35 Correct 97 ms 6816 KB Output is correct
36 Correct 95 ms 7064 KB Output is correct
37 Correct 98 ms 6968 KB Output is correct
38 Correct 0 ms 204 KB Output is correct
39 Correct 95 ms 6948 KB Output is correct
40 Correct 95 ms 6948 KB Output is correct
41 Correct 96 ms 6968 KB Output is correct
42 Correct 93 ms 7316 KB Output is correct