Submission #615856

#	Time	Username	Problem	Language	Result	Execution time	Memory
615856		1bin	Untitled (POI11_rot)	C++14	100 / 100	366 ms	23928 KiB

Main

#include <bits/stdc++.h>

using namespace std;

#define all(v) v.begin(), v.end()
typedef long long ll;
const int base = 1 << 20;
ll n, a[base], lc[base], rc[base], w[base], t, ans;
ll seg[1 << 21];

void dfs(int x){
    cin >> a[x];
    if(a[x]) w[x] = 1;
    else{
        lc[x] = ++t; dfs(lc[x]);
        rc[x] = ++t; dfs(rc[x]);
        if(w[lc[x]] > w[rc[x]]) swap(lc[x], rc[x]);
        w[x] = w[lc[x]] + w[rc[x]];
    }
    return;
}

void upd(int idx, ll v){
    idx += base;
    while(idx){
        seg[idx] += v; idx /= 2;
    }
    return;
}

ll sum(int l, int r){
    ll ret = 0;
    l += base; r += base;
    while(l <= r){
        if(l & 1) ret += seg[l++];
        if(!(r & 1)) ret += seg[r--];
        l /= 2; r /= 2;
    }
    return ret;
}

void f(int x, int v){
    if(a[x]){
        upd(a[x], v); return;
    }
    f(lc[x], v);
    f(rc[x], v);
    return;
}

ll cal(int x){
    if(a[x]) return sum(a[x] + 1, base - 1);
    return cal(lc[x]) + cal(rc[x]);
}

void dfs2(int x){
    if(a[x]) {
        upd(a[x], 1);
        return;
    }
    ll v = 0;
    dfs2(lc[x]);
    f(lc[x], -1);
    dfs2(rc[x]);
    v += cal(lc[x]);
    f(lc[x], 1);
    ans += min(v, w[lc[x]] * w[rc[x]] - v);
    return;
}

int main(void){
    ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    
    cin >> n;
    dfs(++t);
    dfs2(1);
    cout << ans;
    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