#include<bits/stdc++.h>
#include "dreaming.h"
using namespace std;
#define maxn 100005
int head[maxn];
long long len[maxn];
pair<int,long long> rec[maxn];
vector<pair<int,long long> > from[maxn];
vector<int> p[maxn];
vector<long long> a;
void dfs(int x,int last) {
int i;
for(i=0;i<from[x].size();i++) {
if(from[x][i].first!=last) {
len[from[x][i].first] = len[x] + from[x][i].second;
rec[from[x][i].first] = {x, from[x][i].second};
dfs(from[x][i].first,x);
}
}
}
int findhead(int x) {
if(head[x]==x) return x;
return head[x] = findhead(head[x]);
}
bool cmp(int x,int y) {
return x>y;
}
int travelTime(int N,int M,int L,int A[],int B[],int T[]) {
int i,j;
long long sum,now,full,half,ans;
for(i=0;i<N;i++) head[i] = i;
for(i=0;i<M;i++) from[A[i]].push_back({B[i],T[i]}), from[B[i]].push_back({A[i],T[i]}), head[findhead(A[i])] = findhead(B[i]);
for(i=0;i<N;i++) p[findhead(i)].push_back(i);
ans = 0;
for(i=0;i<N;i++) {
if(p[i].size()==0) continue;
for(j=0;j<p[i].size();j++) len[p[i][j]] = 0, rec[p[i][j]] = {-1, -1};
//First
now = p[i][0];
dfs(now,-1);
//Second
for(j=0;j<p[i].size();j++) if(len[p[i][j]]>len[now]) now = p[i][j];
for(j=0;j<p[i].size();j++) len[p[i][j]] = 0;
dfs(now,-1);
//Track
for(j=0;j<p[i].size();j++) if(len[p[i][j]]>len[now]) now = p[i][j];
full = half = len[now]; sum = 0;
while(now!=-1) {
sum += rec[now].first;
now = rec[now].first;
half = min(half,max(sum,full-sum));
}
ans = max(ans,full);
a.push_back(half);
}
sort(&a[0],&a[a.size()],cmp);
if(a.size()>1) ans = max(ans,a[0]+a[1]+L);
if(a.size()>2) ans = max(ans,a[1]+a[2]+L+L);
printf("%lld",ans);
}
Compilation message
dreaming.cpp: In function 'void dfs(int, int)':
dreaming.cpp:13:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(i=0;i<from[x].size();i++) {
~^~~~~~~~~~~~~~~
dreaming.cpp: In function 'int travelTime(int, int, int, int*, int*, int*)':
dreaming.cpp:37:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(j=0;j<p[i].size();j++) len[p[i][j]] = 0, rec[p[i][j]] = {-1, -1};
~^~~~~~~~~~~~
dreaming.cpp:42:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(j=0;j<p[i].size();j++) if(len[p[i][j]]>len[now]) now = p[i][j];
~^~~~~~~~~~~~
dreaming.cpp:43:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(j=0;j<p[i].size();j++) len[p[i][j]] = 0;
~^~~~~~~~~~~~
dreaming.cpp:46:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(j=0;j<p[i].size();j++) if(len[p[i][j]]>len[now]) now = p[i][j];
~^~~~~~~~~~~~
dreaming.cpp:60:1: warning: no return statement in function returning non-void [-Wreturn-type]
}
^
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Execution timed out |
1086 ms |
17776 KB |
Time limit exceeded |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Execution timed out |
1086 ms |
17776 KB |
Time limit exceeded |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Execution timed out |
1086 ms |
17776 KB |
Time limit exceeded |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Execution timed out |
1072 ms |
9672 KB |
Time limit exceeded |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Execution timed out |
1086 ms |
17776 KB |
Time limit exceeded |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Execution timed out |
1086 ms |
17776 KB |
Time limit exceeded |
| 2 |
Halted |
0 ms |
0 KB |
- |
