Submission #863217

#	Time	Username	Problem	Language	Result	Execution time	Memory
863217		Ahmed_Solyman	Cijanobakterije (COCI21_cijanobakterije)	C++14	70 / 70	339 ms	16700 KiB

Main

/*
In the name of Allah
made by: Ahmed_Solyman
*/
#include <bits/stdc++.h>
#include <ext/rope>
 
using namespace std;
using namespace __gnu_cxx;
#pragma GCC optimize("-Ofast")
#pragma GCC optimize("-O1")
//-------------------------------------------------------------//
typedef long long ll;
typedef unsigned long long ull;
#define fast ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define PI acos(-1)
#define lb lower_bound
#define ub upper_bound
#define endl '\n'
#define all(v) v.begin(),v.end()
#define allr(v) v.rbegin(),v.rend()
#define sum_to(n) (n*(n+1))/2
#define pb push_back
#define pf push_front
#define fil(arr,x) memset(arr,x,sizeof(arr))
const ll mod=1e9+7;
int dx[8]={0,1,0,-1,1,1,-1,-1};
int dy[8]={1,0,-1,0,1,-1,-1,1};
//-------------------------------------------------------------//
ll lcm(ll a,ll b)
{
    return (max(a,b)/__gcd(a,b))*min(a,b);
}
void person_bool(bool x)
{
    cout<<(x?"YES":"NO")<<endl;
}
const int N=1e5+5;
vector<int>adj[N];
bool vis[N];
int main()
{
    //freopen("input.txt","r",stdin);
    //freopen("output.txt","w",stdout);
    #ifndef ONLINE_JUDGE
    //freopen("input.in", "r", stdin);
    //freopen("output.out", "w", stdout);
    #endif
    fast
    int n,m;cin>>n>>m;
    for(int i=0;i<m;i++){
    	int u,v;cin>>u>>v;
    	adj[u].push_back(v);
    	adj[v].push_back(u);
    }
    int ans=0;
    for(int i=1;i<=n;i++){
    	if(!vis[i]){
	    	map<int,int>dist;
	    	map<int,bool>v;
	    	queue<int>q;
	    	q.push(i);
	    	dist[i]=0;
	    	int mx=0;
	    	int root=0;
	    	while(q.size()){
	    		int x=q.front(); q.pop();
	    		if(dist[x]>=mx){
	    			mx=dist[x];
	    			root=x;
	    		}
	    		vis[x]=1;v[x]=1;
	    		for(auto ch:adj[x]){
	    			if(!v[ch]){
	    				dist[ch]=dist[x]+1;
	    				q.push(ch);
	    			}
	    		}
	    	}
	    	dist[root]=0;
	    	v.clear();
	    	dist.clear();
	    	q.push(root);
	    	dist[root]=0;
	    	mx=0;
	    	while(q.size()){
	    		int x=q.front(); q.pop();
	    		if(dist[x]>=mx){
	    			mx=dist[x];
	    		}
	    		vis[x]=1;v[x]=1;
	    		for(auto ch:adj[x]){
	    			if(!v[ch]){
	    				dist[ch]=dist[x]+1;
	    				q.push(ch);
	    			}
	    		}
	    	}
	    	ans+=mx+1;
    	}
    }
    cout<<ans<<endl;
    return 0;
}

• Subtask 1: 15 / 15
• Subtask 2: 6 / 6
• Subtask 3: 6 / 6
• Subtask 4: 15 / 15
• Subtask 5: 28 / 28