#include<bits/stdc++.h>
using namespace std;
using ll = long long;
const int N=1e6+5;
int n;
pair<int,int> nxt[N];
int deg[N];
queue<int> q;
ll dp[N],dp2[N],dia[N];
ll ans;
template<class T>
struct Vector{
T dat[N];
int sz=0;
void clear(){
sz=0;
}
void push_back(T val){
dat[sz]=val;
sz++;
}
T* begin(){
return dat;
}
T* end(){
return dat+sz;
}
};
Vector<pair<int,ll>> comp;
template<class T>
struct Deque{
T dat[N*2];
int l=0,r=0;
bool empty(){
return l>r;
}
void clear(){
l=0,r=-1;
}
void push_back(T val){
dat[++r]=val;
}
void pop_front(){
l++;
}
void pop_back(){
r--;
}
T front(){
return dat[l];
}
T back(){
return dat[r];
}
};
Deque<pair<ll,int>> dq;
int main(){
cin.tie(nullptr)->sync_with_stdio(false);
cin >> n;
for(int i=1;i<=n;i++){
auto &[v,w]=nxt[i];
cin >> v >> w;
deg[v]++;
}
for(int i=1;i<=n;i++)if(!deg[i])q.emplace(i);
while(!q.empty()){
int u=q.front();
q.pop();
auto [v,w]=nxt[u];
dp2[v]=max(dp2[v],dp[u]+w);
if(dp[v]<dp2[v])swap(dp[v],dp2[v]);
dia[v]=max({dia[v],dia[u],dp[v]+dp2[v]});
if(--deg[v]==0)q.emplace(v);
}
for(int i=1;i<=n;i++)if(deg[i]){
comp.clear();
ll len=0;
for(int u=i;deg[u];){
comp.push_back({u,len});
deg[u]=0;
auto [v,w]=nxt[u];
len+=w;
u=v;
}
ll res=0;
dq.clear();
for(auto [u,w]:comp){
res=max(res,dia[u]);
ll val=dp[u]-w;
while(!dq.empty()&&dq.back().first<val)dq.pop_back();
dq.push_back({val,u});
}
for(auto [u,w]:comp){
if(dq.front().second==u)dq.pop_front();
res=max(res,w+len+dp[u]+dq.front().first);
ll val=dp[u]-w-len;
while(!dq.empty()&&dq.back().first<val)dq.pop_back();
dq.push_back({val,u});
}
ans+=res;
}
cout << ans;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
344 KB |
Output is correct |
2 |
Correct |
1 ms |
348 KB |
Output is correct |
3 |
Correct |
1 ms |
348 KB |
Output is correct |
4 |
Correct |
1 ms |
348 KB |
Output is correct |
5 |
Correct |
0 ms |
348 KB |
Output is correct |
6 |
Correct |
0 ms |
368 KB |
Output is correct |
7 |
Correct |
0 ms |
348 KB |
Output is correct |
8 |
Correct |
0 ms |
348 KB |
Output is correct |
9 |
Correct |
1 ms |
476 KB |
Output is correct |
10 |
Correct |
1 ms |
348 KB |
Output is correct |
11 |
Correct |
0 ms |
348 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
360 KB |
Output is correct |
2 |
Correct |
1 ms |
520 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
600 KB |
Output is correct |
2 |
Correct |
1 ms |
604 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
4 ms |
1292 KB |
Output is correct |
2 |
Correct |
6 ms |
2396 KB |
Output is correct |
3 |
Correct |
4 ms |
1372 KB |
Output is correct |
4 |
Correct |
3 ms |
860 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
8 ms |
3552 KB |
Output is correct |
2 |
Correct |
15 ms |
5456 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
31 ms |
10856 KB |
Output is correct |
2 |
Correct |
29 ms |
9688 KB |
Output is correct |
3 |
Correct |
41 ms |
20300 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
74 ms |
19036 KB |
Output is correct |
2 |
Correct |
78 ms |
28268 KB |
Output is correct |
3 |
Correct |
68 ms |
23128 KB |
Output is correct |
4 |
Correct |
107 ms |
51540 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
137 ms |
27884 KB |
Output is correct |
2 |
Correct |
168 ms |
58928 KB |
Output is correct |
3 |
Correct |
118 ms |
39364 KB |
Output is correct |
4 |
Correct |
152 ms |
57128 KB |
Output is correct |
5 |
Correct |
156 ms |
56388 KB |
Output is correct |
6 |
Correct |
192 ms |
50004 KB |
Output is correct |
7 |
Correct |
181 ms |
79440 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
185 ms |
51000 KB |
Output is correct |
2 |
Correct |
154 ms |
50892 KB |
Output is correct |
3 |
Correct |
157 ms |
74576 KB |
Output is correct |
4 |
Correct |
140 ms |
27204 KB |
Output is correct |
5 |
Correct |
151 ms |
60908 KB |
Output is correct |
6 |
Correct |
155 ms |
51028 KB |
Output is correct |
7 |
Correct |
212 ms |
51280 KB |
Output is correct |