Submission #100822

#	Submission time	Handle	Problem	Language	Result	Execution time	Memory
100822	2019-03-14T19:25:46 Z	RafaelSus	Race (IOI11_race)	C++14	Compilation error	0 ms	0 KB

race

#include <iostream>
#include <algorithm>
#include <vector>

using namespace std;

int n,k;
bool used[200002], used_1[200002], used_2[200002];
vector<pair<int,int>>g[200002];
int size[200002];
int tree_centroid;
int best[200002];
const int inf = 1e9;
int ans = 1e9;
/*
void dfs(int v){
	used[v]=true;
	for(auto x:g[v]){
		if(used[x.first])continue;
		dfs(x.first);
		size[v]+=size[x.first];
	}	
	size[v]++;
}
*/
void dfs(int node, int dad = -1)
{
	size[node] = 1;
	for (auto it : g[node])
		if (!used[it.first] && it.first != dad)
		{
			dfs(it.first, node);
			size[node] += size[it.first];
		}
}


void findcentroid(int v, int flo){
	used_1[v]=true;
	int zib=0;
	for(auto x:g[v]){
		if(used_1[x.first])continue;
		if(size[x.first] - 1 >= flo){
			zib++;
			findcentroid(x.first, flo);
			break;
		}
	}
	if(zib==0)
		tree_centroid=v;
}

void dfs2(int x, int p, int cost, int l, vector<pair<int,int>>&to_ans) {
	if (cost <= k) 
		to_ans.push_back(make_pair(cost, l));

	for (auto y : g[x]) {
		if (used_2[y.first] || y.first == p)continue;
		dfs2(y.first, x, cost + y.second, l + 1, to_ans);
	}
}


int solve(int node) {
	dfs(node);
	fill(used_1, used_1 + n, false);
	int zibil = size[node] - 1;
	findcentroid(node, zibil / 2);
	node = tree_centroid;
	best[0] = 0;

	vector<int>del;
	vector<pair<int, int>>to_ans;

	for (auto x : g[node]) {
		int son = x.first;
		int cost = x.second;
		if (used_2[son])continue;
		to_ans.clear();
		dfs2(x.first, node, x.second, 1, to_ans);

		for (auto it : to_ans)
			ans = min(ans, it.second + best[k - it.first]);


		for (auto it : to_ans)
		{
			best[it.first] = min(best[it.first], it.second);
			del.push_back(it.first);
		}
	}
	for (auto it : del)
		best[it] = inf;

	used_2[node] = true;


	for (auto it : g[node])
		if (!used_2[it.first])
			ans = min(ans, solve(it.first));

	return ans;
}


int main(){
	cin>>n>>k;
	for(int i=1;i<n;i++){
		int x,y,z;
		cin>>x>>y>>z;
		g[x].push_back(make_pair(y,z));
		g[y].push_back(make_pair(x,z));
	}

	for (int i = 0; i <= k; i++)best[i] = inf;

	cout << solve(0) << endl;
	return 0;
}

Compilation message

race.cpp: In function 'int solve(int)':
race.cpp:77:7: warning: unused variable 'cost' [-Wunused-variable]
   int cost = x.second;
       ^~~~
/tmp/ccHEU6zA.o: In function `main':
race.cpp:(.text.startup+0x0): multiple definition of `main'
/tmp/ccN0I2nK.o:grader.cpp:(.text.startup+0x0): first defined here
/tmp/ccN0I2nK.o: In function `main':
grader.cpp:(.text.startup+0x20): undefined reference to `best_path(int, int, int (*) [2], int*)'
collect2: error: ld returned 1 exit status