| # | 제출 시각 | 아이디 | 문제 | 언어 | 결과 | 실행 시간 | 메모리 |
|---|---|---|---|---|---|---|---|
| 1319811 | mehralii | 꿈 (IOI13_dreaming) | C++20 | 0 ms | 0 KiB |
#include <bits/stdc++.h>
// #include <ext/pb_ds/assoc_container.hpp>
using namespace std;
// using namespace __gnu_pbds;
// template <typename T>
// using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
#define int long long
#define pb push_back
#define eb emplace_back
#define pf push_front
#define ppb pop_back
#define ppf pop_front
#define ins insert
#define ff first
#define ss second
// mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
constexpr int inf = 1e15, mod = 998244353, maxn = 1000005;
vector<vector<pair<int, int>>> g;
vector<bool> vis;
vector<int> dist;
vector<vector<int>> comp;
void dfs(int u, int p, int col){
vis[u]=true;
comp[col].pb(u);
for (auto [v, w]: g[u]){
if (v !=p){
dist[v]=dist[u]+w;
dfs(v, u, col);
}
}
}
void dfs2(int u, int p){
for (auto [v, w]:g[u]){
if (v != p){
dist[v]=dist[u]+w;
dfs2(v, u);
}
}
}
void dfs3(int u, int p, map<int,int>&dist){
for (auto [v, w]:g[u]){
if (v != p){
dist[v]=dist[u]+w;
dfs3(v, u, dist);
}
}
}
int best(int col){
int a = *comp[col].begin(), b, c;
dist[a]=0;
dfs2(a, -1);
int mx=-inf;
for (int v: comp[col]){
if (dist[v]>mx){
mx=dist[v];
b=v;
}
}
dist[b] = 0;
dfs2(b,-1);
mx=-inf;
for (int v: comp[col]){
if (dist[v]>mx){
mx=dist[v];
c=v;
}
}
map<int, int> distC;
distC[c] = 0;
dfs3(c,-1,distC);
int mn = inf;
for (int u: comp[col]){
mn = min(mn, max(1ll*dist[u],1ll*distC[u]));
}
return mn;
}
int travelTime(int n, int m, int l, int a[],int b[],int t[]){
g.assign(n+1, vector<pair<int,int>>());
vis.assign(n+1, false);
dist.assign(n+1, -inf);
comp.assign(n+1, vector<int>());
for (int i = 0; i < m; i++){
g[a[i]].eb(b[i], t[i]);
g[b[i]].eb(a[i], t[i]);
}
int d=-inf, col=0;
for (int i = 0; i < n; i++){
if (!vis[i]){
dfs(i,-1, col);
int u, mx=-inf;
for (int v: comp[col]){
if (dist[v]>mx){
mx=dist[v];
u=v;
}
}
dfs(u,-1, col);
mx=-inf;
for (int v: comp[col]){
if (dist[v]>mx){
mx=dist[v];
}
}
d = max(d, mx);
col++;
}
}
vector<int> r;
for (int i = 0; i < col; i++){
r.pb(best(i));
}
sort(r.rbegin(), r.rend());
if (col==1){
return d;
} else if (col==2){
return max(d, r[0]+r[1]+l);
} else{
return max({d, r[0]+r[1]+l, r[1]+l+l+r[2]});
}
}
/*
void solve(){
cin >> n >> m >> l;
int a[m], b[m], t[m];
for (int i = 0; i < m; i++){
cin >> a[i] >> b[i] >> t[i];
}
cout << travelTime(n, m, l, a, b, t) << '\n';
}
signed main(){
ios::sync_with_stdio(false);
cin.tie(nullptr);
int t = 1;
// cin >> t;
for (int i = 0; i < t; i++) {
solve();
}
return 0;
}
*/