Submission #287846

#	Time	Username	Problem	Language	Result	Execution time	Memory
287846		zecookiez	Untitled (POI11_rot)	C++17	36 / 100	1090 ms	21496 KiB

Main

#include <bits/stdc++.h>
using namespace std;
template<class C>constexpr int len(const C&c){return int(c.size());}

const int MAXN = 200005;
int N, inp[MAXN], sz[MAXN], L[MAXN], R[MAXN]; long long ans, bit[MAXN];

void update(int pos, int val){
    for(int i = pos; i <= N; i += i & -i) bit[i] += val;
}
long long query(int pos){
    long long tot = 0;
    for(int i = pos; i > 0; i -= i & -i) tot += bit[i];
    return tot;
}

int read_tree(int id){
    cin >> inp[id];
    if(inp[id] != 0){
        L[id] = id;
        R[id] = id;
        sz[id] = 1;
        return id;
    }
    int left = read_tree(id + 1);
    int right = read_tree(left + 1);
    sz[id] = sz[left] + sz[right];
    L[id] = left; R[id] = right;
    return right;
}

vector<int> solve(int id){
    int A = inp[id];
    if(A != 0){
        update(A, 1);
        return {A};
    }
    vector<int> left, right;
    if(sz[L[id]] <= sz[R[id]]){
        left = solve(id + 1);
        for(auto i : left) update(i, -1);
        right = solve(L[id] + 1);
    } else {
        left = solve(L[id] + 1);
        for(auto i : left) update(i, -1);
        right = solve(id + 1);
    }
    long long cur, case1 = 0, case2 = 0;
    for(auto i : left){
        cur = query(i - 1);
        case1 += cur; case2 += len(right) - cur;
    }
    ans += min(case1, case2);
    for(auto i : left) update(i, 1), right.push_back(i);
    return right;
}

int main(){
    cin.sync_with_stdio(0); cin.tie(0); cout.tie(0);
    cin >> N; read_tree(0); solve(0); cout << ans << '\n';
    return 0;
}

• Subtask 1: 9 / 9
• Subtask 2: 9 / 9
• Subtask 3: 9 / 9
• Subtask 4: 9 / 9
• Subtask 5: 0 / 9
• Subtask 6: 0 / 9
• Subtask 7: 0 / 9
• Subtask 8: 0 / 9
• Subtask 9: 0 / 9
• Subtask 10: 0 / 9
• Subtask 11: 0 / 10