Submission #1098532

#	Time	Username	Problem	Language	Result	Execution time	Memory
1098532		BLOBVISGOD	Untitled (POI11_rot)	C++17	100 / 100	377 ms	58196 KiB

Main

#include "bits/stdc++.h"
using namespace std;
#define rep(i,a,b) for(int i=(a); i<(b); ++i)
#define all(x) x.begin(),x.end()
#define sz(x) int(x.size())
typedef long long ll;
typedef unsigned long long ull;
typedef vector<int> vi;
typedef vector<vi> vvi;

#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
 
using namespace __gnu_pbds;
typedef tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update> ordered_multiset;

ordered_multiset nums[int(2e5)];

int main(){
    cin.tie(NULL),cin.sync_with_stdio(false);
    
    int n; cin >> n;
    int m = n*2-2;

    int cc = 0;
    vvi adj(m+1);

    auto build = [&](int& at, auto&& build) -> int {
        int v; cin >> v;
        if (v==0){
            int my = at;
            adj[my].push_back(build(--at,build));
            adj[my].push_back(build(--at,build));
            return my;
        }else{
            at++;
            return v-1;
        }
    };

    build(m,build);

    auto dfs = [&](int at, auto&& dfs) -> array<ll,2> {
        if (at<n){
            nums[cc].insert(at);
            return {0,cc++};
        }else{
            array<ll,2> inds;
            ll ans = 0;
            rep(i,0,2){
                auto ret = dfs(adj[at][i],dfs);
                ans += ret[0];
                inds[i] = ret[1];
            }

            ll minext = 1e18;
            if (sz(nums[inds[0]]) < sz(nums[inds[1]])) swap(inds[0],inds[1]);

            {
                // 
                ll extl = 0, extr = 0;
                for(auto c : nums[inds[1]]){
                    int smaller = nums[inds[0]].order_of_key(c);
                    extl += sz(nums[inds[0]]) - smaller;
                    extr += smaller;
                }
                minext = min(extl, extr);
            }

            // merge small into large
            for(auto c : nums[inds[1]]) nums[inds[0]].insert(c);
            nums[inds[1]].clear();
            return {ans + minext, inds[0]};
        }
    };

    cout << dfs(n*2-2,dfs)[0] << '\n';
}

• 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