Submission #1059981

#	Time	Username	Problem	Language	Result	Execution time	Memory
1059981		Unforgettablepl	Split the Attractions (IOI19_split)	C++17	22 / 100	526 ms	1048576 KiB

split

#include "split.h"
#include <bits/stdc++.h>
using namespace std;

vector<int> find_split(int n, int a, int b, int c, vector<int> p, vector<int> q) {
	vector<pair<int,int>> poss = {{a,1},{b,2},{c,3}};
	sort(poss.begin(), poss.end());
	vector<vector<int>> adj(n);
	for(int i=0;i<p.size();i++)adj[p[i]].emplace_back(q[i]);
	for(int i=0;i<p.size();i++)adj[q[i]].emplace_back(p[i]);
	pair<int,int> answer = {-1,-1};
	{
		bool reiter = false;
		back:
		function<int(int,int)> dfs = [&](int x,int p) {
			int subsize = 1;
			for(int&i:adj[x])if(i!=p)subsize+=dfs(i,x);
			if(subsize>=poss[0].first and n-subsize>=poss[1].first)answer={x,p};
			return subsize;
		};
		dfs(0,-1);
		if(answer.first==-1) {
			if(reiter)return vector(n,0);
			reiter=true;
			swap(poss[1],poss[0]);
			goto back;
		}
	}
	vector<int> res(n,2);
	int curr = 0;
	int currnode = 0;
	int tar = 0;
	function<void(int,int)> dfs = [&](int x,int p) {
		if(curr==tar)return;
		res[x]=currnode;
		curr++;
		for(int&i:adj[x])if(i!=p)dfs(i,x);
	};
	curr = 0;
	currnode = 0;
	tar = poss[0].first;
	dfs(answer.first,answer.second);
	curr = 0;
	currnode = 1;
	tar = poss[1].first;
	dfs(answer.second,answer.first);
	for(int&i:res)i=poss[i].second;
	return res;
}

Compilation message (stderr)

split.cpp: In function 'std::vector<int> find_split(int, int, int, int, std::vector<int>, std::vector<int>)':
split.cpp:9:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    9 |  for(int i=0;i<p.size();i++)adj[p[i]].emplace_back(q[i]);
      |              ~^~~~~~~~~
split.cpp:10:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   10 |  for(int i=0;i<p.size();i++)adj[q[i]].emplace_back(p[i]);
      |              ~^~~~~~~~~

• Subtask 1: 0 / 7
• Subtask 2: 0 / 11
• Subtask 3: 22 / 22
• Subtask 4: 0 / 24
• Subtask 5: 0 / 36