#include <bits/stdc++.h>
using namespace std;
// macros
typedef long long ll;
typedef long double ld;
typedef pair<int, int> ii;
typedef pair<ll, ll> lll;
typedef tuple<int, int, int> iii;
typedef vector<int> vi;
typedef vector<ii> vii;
typedef vector<iii> viii;
typedef vector<ll> vll;
typedef vector<lll> vlll;
#define REP(a,b,c) for(int a=int(b); a<int(c); a++)
#define RE(a,c) REP(a,0,c)
#define RE1(a,c) REP(a,1,c+1)
#define REI(a,b,c) REP(a,b,c+1)
#define REV(a,b,c) for(int a=int(c-1); a>=int(b); a--)
#define FOR(a,b) for(auto& a : b)
#define all(a) a.begin(), a.end()
#define INF 1e18
#define EPS 1e-9
#define pb push_back
#define popb pop_back
#define fi first
#define se second
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
// input
template<class T> void IN(T& x) {cin >> x;}
template<class H, class... T> void IN(H& h, T&... t) {IN(h); IN(t...); }
// output
template<class T1, class T2> void OUT(const pair<T1,T2>& x);
template<class T> void OUT(const vector<T>& x);
template<class T> void OUT(const T& x) {cout << x;}
template<class H, class... T> void OUT(const H& h, const T&... t) {OUT(h); OUT(t...); }
template<class T1, class T2> void OUT(const pair<T1,T2>& x) {OUT(x.fi,' ',x.se);}
template<class T> void OUT(const vector<T>& x) {RE(i,x.size()) OUT(i==0?"":" ",x[i]);}
template<class... T> void OUTL(const T&... t) {OUT(t..., "\n"); }
template<class H> void OUTLS(const H& h) {OUTL(h); }
template<class H, class... T> void OUTLS(const H& h, const T&... t) {OUT(h,' '); OUTLS(t...); }
// dp
template<class T> bool ckmin(T&a, T&b) { bool bl = a > b; a = min(a,b); return bl;}
template<class T> bool ckmax(T&a, T&b) { bool bl = a < b; a = max(a,b); return bl;}
void program();
signed main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
program();
}
//===================//
// begin program //
//===================//
const int MX = 2e6+10;
const int N = (1<<20);
int n, edges;
int a[MX], b[MX], l[MX], rev[MX];
vi adj[MX];
// finding cycles
bitset<MX> visited;
int cycleStart;
int skippedEdge = -1;
vii cycle;
bool dfsVisit(int u, int pe) {
if(visited[u]) {
cycleStart = u;
skippedEdge = pe;
return true;
}
bool res = false;
visited[u] = 1;
FOR(e,adj[u]) {
if(e == pe || e == skippedEdge) continue;
if(dfsVisit(b[e], rev[e])) {
cycle.pb({b[e], l[e]});
if(u != cycleStart)
res = true;
}
}
return res;
}
// finding depth
ll curBest = 0;
lll combine(lll x, ll y) {return {max(x.fi,y), max(min(x.fi,y),x.se)};}
ll dfsDepth(int u, int pe, int i1, int i2) {
ll res = 0;
lll p = {-INF,-INF};
FOR(e,adj[u]) {
if(e == pe) continue;
if(b[e] == i1) continue;
if(b[e] == i2) continue;
ll d = l[e] + dfsDepth(b[e],rev[e],i1,i2);
res = max(res, d);
combine(p,d);
}
curBest = max(curBest, p.fi + p.se);
return res;
}
void program() {
IN(n);
RE1(i,n) {
IN(a[edges],l[edges]); b[edges] = i;
adj[a[edges]].pb(edges);
rev[edges ] = edges+1;
rev[edges+1] = edges;
a[edges+1] = b[edges], b[edges+1] = a[edges], l[edges+1] = l[edges];
adj[a[edges+1]].pb(edges+1);
edges += 2;
}
ll ans = 0;
RE1(i,n) {
if(visited[i]) continue;
// find the cycle
curBest = 0;
cycle.clear();
dfsVisit(i,-1);
// fill a, b and c
vll A, B, C; B.pb(0);
ll m = cycle.size(), totB = 0;
FOR(u,cycle) A.pb(u.fi), B.pb(u.se);
RE(i,m) C.pb(dfsDepth(A[i], -1, A[(i+1)%m], A[(i-1+m)%m]));
FOR(i,B) totB += i;
RE(i,m) B[i+1] += B[i];
RE(i,m) REP(j,i+1,m) {
curBest = max(curBest, B[j]-B[i]+C[i]+C[j]);
curBest = max(curBest, totB-B[j]+B[i]+C[i]+C[j]);
}
ans += curBest;
}
OUTL(ans);
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
30 ms |
47308 KB |
Output is correct |
| 2 |
Incorrect |
46 ms |
47308 KB |
Output isn't correct |
| 3 |
Correct |
45 ms |
47380 KB |
Output is correct |
| 4 |
Correct |
30 ms |
47248 KB |
Output is correct |
| 5 |
Correct |
30 ms |
47284 KB |
Output is correct |
| 6 |
Correct |
30 ms |
47320 KB |
Output is correct |
| 7 |
Correct |
30 ms |
47236 KB |
Output is correct |
| 8 |
Correct |
29 ms |
47296 KB |
Output is correct |
| 9 |
Correct |
30 ms |
47324 KB |
Output is correct |
| 10 |
Incorrect |
31 ms |
47256 KB |
Output isn't correct |
| 11 |
Correct |
32 ms |
47296 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
29 ms |
47436 KB |
Output is correct |
| 2 |
Correct |
27 ms |
47360 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
29 ms |
47448 KB |
Output is correct |
| 2 |
Correct |
34 ms |
47856 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
53 ms |
48760 KB |
Output is correct |
| 2 |
Correct |
380 ms |
51932 KB |
Output is correct |
| 3 |
Correct |
40 ms |
48936 KB |
Output is correct |
| 4 |
Incorrect |
33 ms |
48076 KB |
Output isn't correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
571 ms |
53644 KB |
Output is correct |
| 2 |
Correct |
798 ms |
57480 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
607 ms |
63852 KB |
Output is correct |
| 2 |
Execution timed out |
2065 ms |
72612 KB |
Time limit exceeded |
| 3 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Execution timed out |
2007 ms |
75452 KB |
Time limit exceeded |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
342 ms |
115740 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Runtime error |
366 ms |
131076 KB |
Execution killed with signal 9 |
| 2 |
Halted |
0 ms |
0 KB |
- |
