Submission #410029

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
410029	2021-05-21T21:28:14 Z	dreezy	Simurgh (IOI17_simurgh)	C++17	Compilation error	0 ms	0 KB

simurgh

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

struct UnionFind{
	vector<int> height, parent;
	
	void init(int n){
		height.assign(n, 0);
		parent.assign(n,0);
		for(int i =0; i<n;i++)
			parent[i] = i;
	}
	
	
	int getRoot(int n){
		if(parent[n] != n)
			return parent[n] = getRoot(parent[n]);
		return parent[n];
	}
	
	bool isSame(int n1, int n2){
		return getRoot(n1) == getRoot(n2);
	}
	
	void join(int n1, int n2){
		int r1 = getRoot(n1);
		int r2 = getRoot(n2);
		
		if(height[r1] > height[r2]){
			parent[r2] = r1;
			height[r1] = max(height[r1], height[r2]+1);
		}
		else{
			parent[r1] = r2;
			height[r2] = max(height[r2], height[r1]+1);	
		}
	}
	
};

vector<int> find_roads(int n, vector<int> u, vector<int> v ){
	vector<int> is_royal;
	int m = u.size();
	set<int> dontknow;
	for(int i =0; i< m; i++)
		dontknow.insert(i);
	
	/////////
	
	while(true){
		int curcheck = -1;
		int prevans = -1;
		int prevcheck = -1;
		
		UnionFind uf;
		uf.init(n);
		vector<int> roads;
		for(int i : is_royal){
				uf.join(u[i], v[i]);
				roads.push_back(i);
		}
		
		for(int i : dontknow){
			
			if(!uf.isSame(u[i], v[i]) && prevcheck != i){
				uf.join(u[i], v[i]);
				roads.push_back(i);
				curcheck = i;
				
				if(roads.size() == n-1)
					break;
			}
		}
		
		int ans = count_common_roads(roads);
		if(ans == n-1)
			return roads;
		if(prevans == -1){
			prevans = ans;
			continue;
		}
		
		if(ans == prevans+1){
			dontknow.erase(prevcheck);
			is_royal.push_back(prevcheck);
		}
		else if(ans==prevans -1){
			dontknow.erase(prevcheck);
		}
		prevcheck = curcheck;
	}
	return vector<int>();
	
	
}

Compilation message

simurgh.cpp: In function 'std::vector<int> find_roads(int, std::vector<int>, std::vector<int>)':
simurgh.cpp:70:21: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   70 |     if(roads.size() == n-1)
      |        ~~~~~~~~~~~~~^~~~~~
simurgh.cpp:75:13: error: 'count_common_roads' was not declared in this scope
   75 |   int ans = count_common_roads(roads);
      |             ^~~~~~~~~~~~~~~~~~