Submission #502661

#	Time	Username	Problem	Language	Result	Execution time	Memory
502661		NintsiChkhaidze	Dreaming (IOI13_dreaming)	C++14	100 / 100	122 ms	25944 KiB

dreaming

#include "dreaming.h"
#include <bits/stdc++.h>
#define s second
#define f first
#define pb push_back
#define ll long long
using namespace std;

const int N = 100005;
vector <pair<int,ll> > v[N];
vector <ll> vec;
int fix[N],I;
ll D,R,dis[N][5];

void dfs(int x,ll d,int par,int k){
	fix[x] = 1;
	if (d > D) {I = x,D = d;}
	for (int j=0;j<v[x].size();j++){
		int to = v[x][j].f,w = v[x][j].s;
		if (to == par) continue;
		if (k) dis[to][k] = dis[x][k] + w;
		if (k == 2) {
			R = min(R,max(dis[x][1],dis[x][2]));
			// cout<<"x = "<<x<<" "<<dis[x][1]<<" "<<dis[x][2]<<endl;
		}
		dfs(to,d + w,x,k);
	}
}
bool cmp(int a,int b){
	if (a > b) return 1;
	return 0;
}
int travelTime(int n, int m, int L, int A[], int B[], int T[]) {
	for (int i = 0; i < m; i++){
		v[A[i]].pb({B[i],T[i]});
		v[B[i]].pb({A[i],T[i]});
	}

	ll ans=0;
	for (int i = 0; i < n; i++){
		if (fix[i])continue;
		if (!v[i].size()){
			fix[i]=1;
			vec.pb(0);
			continue;
		}
		D = 0;
		dfs(i,0,i,0);
		D = 0;
		int ind = I;
		dfs(ind,0,ind,1);
		D = 0;
		dfs(ind,0,ind,0);
		D = 0;
		R = 1e9;
		dfs(I,0,I,2);
		ans = max(D,ans);
		vec.pb(R);
	}

	sort(vec.begin(),vec.end(),cmp);
	if (vec.size() >= 2) ans = max(ans,vec[0] + vec[1] + L);
	if (vec.size() >= 3) ans = max(ans,vec[1] + vec[2] + 2*L);
	return ans;
}

Compilation message (stderr)

dreaming.cpp: In function 'void dfs(int, long long int, int, int)':
dreaming.cpp:18:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   18 |  for (int j=0;j<v[x].size();j++){
      |               ~^~~~~~~~~~~~

• Subtask 1: 14 / 14
• Subtask 2: 10 / 10
• Subtask 3: 23 / 23
• Subtask 4: 18 / 18
• Subtask 5: 12 / 12
• Subtask 6: 23 / 23