Submission #863748

#	Time	Username	Problem	Language	Result	Execution time	Memory
863748		Huseyn123	Dreaming (IOI13_dreaming)	C++17	100 / 100	54 ms	15060 KiB

dreaming

#include "dreaming.h"
#include <bits/stdc++.h>
#define MAX 100001
#define INF INT_MAX
#define MOD 1000000007
#define mp make_pair
#define mt make_tuple
#define pb push_back
#define ins insert
#define ff first
#define ss second
#define gett(x,m) get<m>(x)
#define all(a) a.begin(),a.end()
#define lb(a,b) lower_bound(all(a),b)
#define ub(a,b) upper_bound(all(a),b)
#define sortv(a) sort(all(a))
#define sorta(a,sz) sort(a,a+sz)
#define inputar(a,b){\
    for(int i=0;i<b;i++){\
        cin >> a[i];\
    }\
}
#define inputvec(a,b){\
    for(int i=0;i<b;i++){\
        ll num;\
        cin >> num;\
        a.pb(num);\
    }\
}
#define outputar(a,b){\
    for(int i=0;i<b;i++){\
        cout << a[i] << " ";\
    }\
    cout << "\n";\
}
#define outputvec(a){\
    for(auto x:a){\
        cout << x << " ";\
    }\
    cout << "\n";\
}
#define reset(a,n,v){\
    for(int i=0;i<n;i++){\
        a[i]=v;\
    }\
}
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef tuple<ll,ll,ll> tll;
typedef pair<ll,ll> pll;
typedef pair<int,int> pii;
typedef double db;
typedef long double ldb;
inline void USACO(string filename){
  freopen((filename+".in").c_str(),"r",stdin);
  freopen((filename+".out").c_str(),"w",stdout);
}
vector<vector<pii>> g; 
vector<int> used; 
vector<int> e; 
vector<int> dist;
vector<int> pre;
void dfs(int v,int prev){
	e.pb(v);
	used[v]=1; 
	for(auto x:g[v]){
		if(x.ff==prev){
			continue;
		}
		dist[x.ff]=dist[v]+x.ss;
		dfs(x.ff,v);
	}
}
void dfs1(int v,int prev){
	pre[v]=prev;
	for(auto x:g[v]){
		if(x.ff==prev){
			continue;
		}
		dist[x.ff]=dist[v]+x.ss;
		dfs1(x.ff,v);
	}
}
int travelTime(int N, int M, int L, int A[], int B[], int T[]) {
	int res;
	g.resize(N);
	dist.resize(N,0); 
	used.resize(N,0);
	pre.resize(N,0);
	for(int i=0;i<M;i++){
		g[A[i]].pb(mp(B[i],T[i])); 
		g[B[i]].pb(mp(A[i],T[i]));
	} 
	int maxd=0;
	vector<int> c;
	for(int i=0;i<N;i++){
		if(used[i]==0){
			e.clear();
			dfs(i,-1); 
			int maxd1,ind;
			maxd1=-1; 
			for(auto x:e){
				if(dist[x]>maxd1){
					maxd1=dist[x]; 
					ind=x;
				}
				dist[x]=0;
			}
			dfs1(ind,-1); 
			maxd1=-1; 
			int ind1; 
			for(auto x:e){
				if(dist[x]>maxd1){
					maxd1=dist[x]; 
					ind1=x;
				}
			}
			maxd=max(maxd,maxd1);
			int ind2=ind1;
			int h=dist[ind1]-dist[ind];
			while(ind1!=ind){
				h=min(h,max(dist[ind2]-dist[ind1],dist[ind1]-dist[ind]));
				ind1=pre[ind1]; 
			}
			c.pb(h);
		}
	}
	sortv(c);
	reverse(all(c));
	if(c.size()==1){
		res=c[0];
	}
	else{
		res=c[0]+c[1]+L;
	}
	if(c.size()>2){
		res=max(res,c[1]+c[2]+2*L);
	}
	res=max(maxd,res);
	return res;
}
/*
int main(){
	int n,m,k; 
	cin >> n >> m >> k;
	int A[m],B[m],T[m];
	for(int i=0;i<m;i++){
		cin >> A[i] >> B[i] >> T[i];
	}
	cout << travelTime(n,m,k,A,B,T);
}
*/

Compilation message (stderr)

dreaming.cpp: In function 'int travelTime(int, int, int, int*, int*, int*)':
dreaming.cpp:121:19: warning: 'ind1' may be used uninitialized in this function [-Wmaybe-uninitialized]
  121 |    int h=dist[ind1]-dist[ind];
      |                   ^
dreaming.cpp:122:14: warning: 'ind' may be used uninitialized in this function [-Wmaybe-uninitialized]
  122 |    while(ind1!=ind){
      |          ~~~~^~~~~

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