#include<bits/stdc++.h>
#define fi first
#define se second
using namespace std;
const int N=1e6;
vector<pair<int,int>> e[N+10];
int f[N+10];
int l[N+10];
bool vis_fill[N+10];
bool vis_s[N+10];
bool on_cycle[N+10];
vector<int> t;
void dfs_fill(int x)
{
t.push_back(x);
vis_fill[x]=true;
for(auto v:e[x])
{
if(!vis_fill[v.fi])
dfs_fill(v.fi);
}
return;
}
pair<long long,long long> dfs_tree(int x)
{
on_cycle[x]=true;
pair<long long,long long> ans={0,0};
for(auto v:e[x])
{
if(on_cycle[v.fi])
continue;
auto tmp=dfs_tree(v.fi);
ans.fi=max({ans.fi,tmp.fi,ans.se+tmp.se+v.se});
ans.se=max(ans.se,tmp.se+v.se);
}
ans.fi=max(ans.fi,ans.se);
return ans;
}
long long solve()
{
long long ans=0;
int c;
for(int i=t[0];true;i=f[i])
{
if(vis_s[i])
{
c=i;
break;
}
vis_s[i]=true;
}
long long l_all=l[c];
on_cycle[c]=true;
for(int i=f[c];i!=c;l_all+=l[i],i=f[i])
on_cycle[i]=true;
long long mx=0,mn=0;
int x=c;
do{
x=f[x];
auto ww=dfs_tree(x);
ans=max(ans,ww.fi);
ans=max({ans,mx+ww.se,mn+ww.se});
mx=max(mx,ww.se)+l[x];
mn=max(mn,ww.se+l_all)-l[x];
}while(x!=c);
return ans;
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
int n;
cin>>n;
for(int i=1;i<=n;i++)
{
int a,b;
cin>>a>>b;
f[i]=a;
l[i]=b;
e[i].emplace_back(a,b);
e[a].emplace_back(i,b);
}
long long ans=0;
for(int i=1;i<=n;i++)
{
if(!vis_fill[i])
{
t.clear();
dfs_fill(i);
ans+=solve();
}
}
cout<<ans<<"\n";
return 0;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
16 ms |
23756 KB |
Output is correct |
2 |
Correct |
15 ms |
23768 KB |
Output is correct |
3 |
Correct |
15 ms |
23824 KB |
Output is correct |
4 |
Correct |
14 ms |
23800 KB |
Output is correct |
5 |
Correct |
15 ms |
23792 KB |
Output is correct |
6 |
Correct |
15 ms |
23720 KB |
Output is correct |
7 |
Correct |
15 ms |
23736 KB |
Output is correct |
8 |
Correct |
15 ms |
23808 KB |
Output is correct |
9 |
Correct |
15 ms |
23800 KB |
Output is correct |
10 |
Correct |
14 ms |
23756 KB |
Output is correct |
11 |
Correct |
14 ms |
23796 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
14 ms |
23816 KB |
Output is correct |
2 |
Correct |
14 ms |
23808 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
14 ms |
23944 KB |
Output is correct |
2 |
Correct |
16 ms |
24204 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
22 ms |
24864 KB |
Output is correct |
2 |
Correct |
32 ms |
26952 KB |
Output is correct |
3 |
Correct |
26 ms |
25300 KB |
Output is correct |
4 |
Correct |
20 ms |
24560 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
38 ms |
27932 KB |
Output is correct |
2 |
Correct |
51 ms |
29956 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
99 ms |
35676 KB |
Output is correct |
2 |
Correct |
106 ms |
38180 KB |
Output is correct |
3 |
Correct |
122 ms |
44488 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
154 ms |
43796 KB |
Output is correct |
2 |
Correct |
210 ms |
60020 KB |
Output is correct |
3 |
Correct |
221 ms |
63084 KB |
Output is correct |
4 |
Correct |
267 ms |
76152 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
344 ms |
81304 KB |
Output is correct |
2 |
Correct |
823 ms |
100116 KB |
Output is correct |
3 |
Correct |
294 ms |
63244 KB |
Output is correct |
4 |
Correct |
389 ms |
88520 KB |
Output is correct |
5 |
Correct |
384 ms |
89908 KB |
Output is correct |
6 |
Correct |
1045 ms |
72720 KB |
Output is correct |
7 |
Correct |
434 ms |
105004 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
421 ms |
131076 KB |
Execution killed with signal 9 |
2 |
Halted |
0 ms |
0 KB |
- |