#include<bits/stdc++.h>
#define endl '\n'
using namespace std;
void speed()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
/*#ifdef ONLINE_JUDGE
freopen("taxi.in", "r", stdin);
freopen("taxi.out", "w", stdout);
#endif
*/
}
struct cell
{
int to,cost;
};
int n,m,l,a[200005],b[200005],t[200005],used[200005],lead[200005],dp[200005],mid,mind1,mind2,mind3;
vector<cell>v[200005];
void read()
{
cin>>n>>m>>l;
for(int i=0;i<m;i++)
{
cin>>a[i]>>b[i]>>t[i];
}
}
void make_dp(int beg)
{
used[beg]=1;
cell w;
for(int i=0;i<v[beg].size();i++)
{
w=v[beg][i];
if(!used[w.to])
{
make_dp(w.to);
dp[beg]=max(dp[beg],dp[w.to]+w.cost);
}
}
}
void find_mid(int beg,int izm)
{
used[beg]=1;
cell w;
int ma=0,sma=0;
cell ind;
for(int i=0;i<v[beg].size();i++)
{
w=v[beg][i];
if(dp[w.to]>ma)
{
ma=dp[w.to];
ind=w;
}
}
for(int i=0;i<v[beg].size();i++)
{
w=v[beg][i];
if(w.to!=ind.to&&dp[w.to]+w.cost>sma)
{
sma=dp[w.to]+w.cost;
}
}
izm=max(izm,sma)+ind.cost;
if(dp[beg]<=max(izm,ma))
{
mid=beg;
}
else
{
find_mid(w.to,izm);
}
}
void make_lead(int beg,int le)
{
used[beg]=2;
lead[beg]=le;
cell w;
for(int i=0;i<v[beg].size();i++)
{
w=v[beg][i];
if(used[w.to]<2)
{
make_lead(w.to,le);
}
}
}
void find_max_lead()
{
int ma=0,ind=0;
for(int i=0;i<n;i++)
{
if(ma<dp[lead[i]])
{
ma=dp[lead[i]];
ind=lead[i];
}
}
mind1=ind;
ind=0;
ma=0;
for(int i=0;i<n;i++)
{
if(lead[i]!=mind1&&ma<dp[lead[i]])
{
ma=dp[lead[i]];
ind=lead[i];
}
}
mind2=ind;
ind=0;
ma=0;
for(int i=0;i<n;i++)
{
if(lead[i]!=mind1&&lead[i]!=mind2&&ma<dp[lead[i]])
{
ma=dp[lead[i]];
ind=lead[i];
}
}
mind3=ind;
}
int travelTime(int N,int M,int L,int A[],int B[],int T[])
{
n=N;
m=M;
l=L;
for(int i=0;i<m;i++)
{
a[i]=A[i];
b[i]=B[i];
t[i]=T[i];
cell g;
g.to=b[i];
g.cost=t[i];
v[a[i]].push_back(g);
g.to=a[i];
v[b[i]].push_back(g);
}
for(int i=0;i<n;i++)
{
if(!used[i])make_dp(i);
}
memset(used,0,sizeof(used));
for(int i=0;i<n;i++)
{
if(!used[i])
{
find_mid(i,0);
make_lead(i,mid);
mid=0;
}
}
memset(used,0,sizeof(used));
memset(dp,0,sizeof(dp));
for(int i=0;i<n;i++)
{
if(!used[lead[i]])make_dp(lead[i]);
}
find_max_lead();
return max(dp[mind1]+dp[mind2]+l,dp[mind2]+dp[mind3]+2*l);
}
/*int main()
{
speed();
read();
travelTime(n,m,l,a,b,t);
return 0;
}
*/
Compilation message
dreaming.cpp: In function 'void make_dp(int)':
dreaming.cpp:33:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<cell>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
33 | for(int i=0;i<v[beg].size();i++)
| ~^~~~~~~~~~~~~~
dreaming.cpp: In function 'void find_mid(int, int)':
dreaming.cpp:49:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<cell>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
49 | for(int i=0;i<v[beg].size();i++)
| ~^~~~~~~~~~~~~~
dreaming.cpp:58:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<cell>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
58 | for(int i=0;i<v[beg].size();i++)
| ~^~~~~~~~~~~~~~
dreaming.cpp: In function 'void make_lead(int, int)':
dreaming.cpp:81:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<cell>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
81 | for(int i=0;i<v[beg].size();i++)
| ~^~~~~~~~~~~~~~
dreaming.cpp: In function 'void find_mid(int, int)':
dreaming.cpp:66:21: warning: 'ind.cell::cost' may be used uninitialized in this function [-Wmaybe-uninitialized]
66 | izm=max(izm,sma)+ind.cost;
| ~~~~~~~~~~~~^~~~~~~~~
dreaming.cpp:67:14: warning: 'w.cell::to' may be used uninitialized in this function [-Wmaybe-uninitialized]
67 | if(dp[beg]<=max(izm,ma))
| ~~~~~~^
dreaming.cpp:61:9: warning: 'ind.cell::to' may be used uninitialized in this function [-Wmaybe-uninitialized]
61 | if(w.to!=ind.to&&dp[w.to]+w.cost>sma)
| ^~
/usr/bin/ld: /tmp/ccxKgpAt.o: in function `main':
grader.c:(.text.startup+0xd1): undefined reference to `travelTime'
collect2: error: ld returned 1 exit status
