Submission #287870

#	Time	Username	Problem	Language	Result	Execution time	Memory
287870		zecookiez	Untitled (POI11_rot)	C++17	100 / 100	168 ms	17656 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, id, cur, arr[MAXN], L[2*MAXN], R[2*MAXN], LL[2*MAXN], RR[2*MAXN], bit[MAXN];
long long ans;

void update(int pos, int val){
    for(int i = pos; i <= N; i += i & -i) bit[i] += val;
}
int query(int pos){
    int tot = 0; for(int i = pos; i > 0; i &= i - 1) tot += bit[i];
    return tot;
}

void read_tree(int node){
    int A; cin >> A;
    L[node] = cur;
    if(A != 0){
        arr[cur++] = A; R[node] = cur; return;
    }
    LL[node] = ++id; read_tree(id);
    RR[node] = ++id; read_tree(id);
    R[node] = cur;
}

void solve(int id){
    if(R[id] - L[id] == 1){
        update(arr[L[id]], 1); return;
    }
    int SZ, left = LL[id], right = RR[id];
    long long cur, case1 = 0, case2 = 0;
    int A = L[left], B = R[left], C = L[right], D = R[right];
    if(B - A <= D - C){
        solve(left); for(int i = A; i < B; ++i) update(arr[i], -1);
        solve(right); SZ = D - C;
        for(int i = A; i < B; ++i){
            cur = query(arr[i] - 1);
            case1 += cur; case2 += SZ - cur;
        }
        for(int i = A; i < B; ++i) update(arr[i], 1);
    } else {
        solve(right); for(int i = C; i < D; ++i) update(arr[i], -1);
        solve(left); SZ = B - A;
        for(int i = C; i < D; ++i){
            cur = query(arr[i] - 1);
            case1 += cur; case2 += SZ - cur;
        }
        for(int i = C; i < D; ++i) update(arr[i], 1);
    }
    ans += min(case1, case2);
}

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: 9 / 9
• Subtask 6: 9 / 9
• Subtask 7: 9 / 9
• Subtask 8: 9 / 9
• Subtask 9: 9 / 9
• Subtask 10: 9 / 9
• Subtask 11: 10 / 10