| # | Time | Username | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 1155855 | AmirMakaM | Dreaming (IOI13_dreaming) | C++20 | 0 ms | 0 KiB |
#include <bits/stdc++.h>
//#include "dreaming.h"
using namespace std;
#define ull unsigned long long
#define ll long long
#define ld long double
#define pb push_back
#define f first
#define s second
#define sz(x) (int)x.size()
#define all(x) x.begin(),x.end()
#define pii pair<int,int>
#define pll pair<ll,ll>
#define pld pair<ld,ld>
#define pdd pair<double,double>
#define mp make_pair
#define AmirMakaM ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0)
//#define int long long
// solve it
const ull SEED = chrono::steady_clock::now().time_since_epoch().count();
mt19937_64 mrand(SEED);
ull rnd(ull x = ~(0ull)) {return mrand() % x;}
const ll MOD = 998244353;
const ll INF = 1e16+20;
const int inf = 1e9 + 7;
const ll N = 1e5+1;
const ll M = 2e3+1;
const double pi = 2*acos(0.0);
const int dx[] = {1,-1,0,0}, dy[] = {0,0,1,-1};
int dp[2][N], mx, res;
vector<pii> g[N];
bool used[N];
/*
void calc(int v) {
used[v] = 1;
dp[0][v] = dp[1][v] = 0;
int mx1 = 0, mx2 = 0;
for(pii it:g[v]) {
if(used[it.f]) continue;
calc(it.f);
if(dp[0][it.f]+it.s > mx2) mx2 = dp[0][it.f]+it.s;
else if(dp[0][it.f]+it.s > mx1) mx1 = dp[0][it.f]+it.s;
dp[0][v] = max(dp[0][it.f]+it.s,dp[0][v]);
}
res = max(res,mx1+mx2);
}
void dfs(int v, int pr = -1) {
//cout << v << " : " << dp[0][v] << " " << dp[1][v] << '\n';
vector<pair<int,pii>> t;
for(pii it:g[v]) {
if(pr == it.f) continue;
t.pb({dp[0][it.f]+it.s,{it.f,it.s}});
}
t.pb({0,{0,0}});
sort(all(t));
mx = min(mx,max(dp[1][v],dp[0][v]));
for(int i=1; i<sz(t); i++) {
//cout << t[i].s.s << " " << t[i].s.f << " " << t[i].f << '\n';
if(i<sz(t)-1) {
dp[1][t[i].s.f] = max(t.back().f,dp[1][v]) + t[i].s.s;
} else {
dp[1][t[i].s.f] = max(t[i-1].f,dp[1][v]) + t[i].s.s;
}
}
for(pii it:g[v]) {
if(pr == it.f) continue;
dfs(it.f,v);
}
}
*/
int cmp[N], cnt = 0, k[N];
int dfs(int v, int pr = -1) {
if(!used[v]) k[v] = cnt;
used[v] = 1;
int mx = 0;
for(pii it:g[v]) {
if(it.f == pr) continue;
mx = max(mx,dfs(it.f,v)+it.s);
}
return mx;
}
int travelTime(int n,int m,int l,int A[], int B[],int T[]) {
for(int i=0; i<m; i++) {
g[A[i]+1].pb({B[i]+1,T[i]});
g[B[i]+1].pb({A[i]+1,T[i]});
}
vector<int> ans;
for(int i=1; i<=n; i++) used[i] = 0;
/*res = 0;
for(int i=1; i<=n; i++) {
if(used[i]) continue;
calc(i);
mx = inf;
dfs(i);
//cout << i << " : " << mx << '\n';
ans.pb(mx);
}*/
for(int i=1; i<=n; i++) {
cmp[i] = inf;
}
for(int i=1; i<=n; i++) {
if(!used[i]) {
cnt++;
}
cmp[k[i]] = min(cmp[k[i]],dfs(i));
res = max(res,dfs(i));
}
for(int i=1; i<=cnt; i++) ans.pb(cmp[i]);
sort(all(ans));
if(n-1-m>=2) res = max(res,ans.back() + ans[sz(ans)-2] + l);
return res;
}
int main() {
AmirMakaM;
srand(SEED);
/*//freopen("bulk.in", "r", stdin);
//freopen("bulk.out", "w", stdout);
int ttt = 1;
//cin >> ttt;
while(ttt--) {
solve();
}*/
int n, m, l;
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';
}