Submission #1729800

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Source Code Expand

#include<bits/stdc++.h>
#define vi vector<int>
#define vvi vector<vector<int> >
#define vl vector<ll>
#define vvl vector<vector<ll>>
#define vb vector<bool>
#define vc vector<char>
#define vs vector<string>
using ll = long long;
using ld =long double;
//#define int ll
#define INF 1e9
#define EPS 0.0000000001
#define rep(i,n) for(int i=0;i<n;i++)
#define loop(i,s,n) for(int i=s;i<n;i++)
#define all(in) in.begin(), in.end()
template<class T, class S> void cmin(T &a, const S &b) { if (a > b)a = b; }
template<class T, class S> void cmax(T &a, const S &b) { if (a < b)a = b; }
#define MAX 9999999
using namespace std;
typedef pair<int, int> pii;
typedef pair<int,pii> piii;
vector<vector<int>>edge;
vector<int>d;
int ans;
int n;
void dfs(int v,int num){
    if(n<num)return;
    d[v]=num;
    rep(i,edge[v].size()){
        int nv=edge[v][i];
        if(d[nv]==num)continue;
        else if(d[nv]!=INF){
            cmax(ans,abs(d[nv]-num)+1);
        }else{
            dfs(nv,num+1);
        }
    }
}
signed main(){
    cin>>n;
    vector<vector<int>>v(n,vector<int>());
    vi t(n,INF);
    edge=v;
    d=t;
    rep(i,n){
        int a,b; cin>>a>>b;
        --a,--b;
        edge[a].push_back(b);
        edge[b].push_back(a);
    }
    //rep(i,n)if(edge[i].size()>=2)ans++;
    dfs(0,1);
    cout<<ans<<endl;
}

Submission Info

Judge Result