# | Time | Username | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
317230 | zaneyu | Dreaming (IOI13_dreaming) | C++14 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
/*input
12 8 2
0 8 4
8 2 2
2 7 4
5 11 3
5 1 7
1 3 1
1 9 5
10 6 3
*/
//#include "dreaming.h"
#include<bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
#pragma GCC optimize("unroll-loops,no-stack-protector")
//order_of_key #of elements less than x
// find_by_order kth element
#define ll long long
#define ld long double
#define pii pair<int,int>
typedef tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update> indexed_set;
#define f first
#define s second
#define pb push_back
#define REP(i,n) for(int i=0;i<n;i++)
#define REP1(i,n) for(int i=1;i<=n;i++)
#define FILL(n,x) memset(n,x,sizeof(n))
#define ALL(_a) _a.begin(),_a.end()
#define sz(x) (int)x.size()
#define SORT_UNIQUE(c) (sort(c.begin(),c.end()), c.resize(distance(c.begin(),unique(c.begin(),c.end()))))
#define MP make_pair
const ll INF64=4e12;
const int INF=0x3f3f3f3f;
const ll MOD=1e9+7;
const ld PI=acos(-1);
const ld eps=1e-9;
#define lowb(x) x&(-x)
#define MNTO(x,y) x=min(x,(__typeof__(x))y)
#define MXTO(x,y) x=max(x,(__typeof__(x))y)
ll mult(ll a,ll b){
return ((a%MOD)*(b%MOD))%MOD;
}
ll mypow(ll a,ll b){
if(b<=0) return 1;
ll res=1LL;
while(b){
if(b&1){
res=(res*a)%MOD;
}
a=(a*a)%MOD;
b>>=1;
}
return res;
}
const ll maxn=1e5+5;
const ll maxlg=__lg(maxn)+2;
vector<pii> v[maxn];
bool vis[maxn];
int bfs(int u,int dist[]){
queue<int> q;
q.push(u);
dist[u]=0;
int lst=-1;
while(!q.empty()){
int z=q.front();
q.pop();
lst=z;
for(auto x:v[z]){
if(dist[x.f]>dist[z]+x.s){
dist[x.f]=dist[z]+x.s;
q.push(x.f);
}
}
}
return lst;
}
int bfs(int u,int dist[],vector<int> &ppl){
queue<int> q;
q.push(u);
dist[u]=0;
int lst=-1;
while(!q.empty()){
int z=q.front();
q.pop();
ppl.pb(z);
lst=z;
for(auto x:v[z]){
if(dist[x.f]>dist[z]+x.s){
dist[x.f]=dist[z]+x.s;
q.push(x.f);
}
}
}
return lst;
}
int da[maxn],db[maxn],dc[maxn];
vector<int> ppl;
int travelTime(int n, int m, int l, int A[], int B[], int T[]) {
REP(i,m){
v[A[i]].pb({B[i],T[i]});
v[B[i]].pb({A[i],T[i]});
}
vector<int> dst;
REP(i,n) da[i]=db[i]=dc[i]=INF,vis[i]=0;
REP(i,n){
if(!vis[i]){
int u=bfs(i,dc);
int vv=bfs(u,da);
ppl.clear();
bfs(vv,db,ppl);
int mn=INF;
for(auto x:ppl){
vis[x]=1;
MNTO(mn,max(da[x],db[x]));
}
//cout<<mn<<'\n';
//cout<<'\n';
dst.pb(mn);
}
}
sort(ALL(dst));
reverse(ALL(dst));
int mx=dst[0];
if(sz(dst)>=2) MXTO(mx,dst[0]+dst[1]+l);
if(sz(dst)>=3) MXTO(mx,dst[1]+dst[2]+2*l);
return mx;
}