Cod sursa(job #2306416)

Utilizator BlaugranasEnal Gemaledin Blaugranas Data 22 decembrie 2018 12:09:11
Problema Diametrul unui arbore Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 0.67 kb
#include<cstdio>
int i,n,c[100001],v[100001],l,d,a[100000],b[100000],w[100001],*g[100001],o[500000],p,u;
void B(int t)
{
	int i,k;
    for(i=1;i<=n;i++)
        c[i]=v[i]=0;
    for(o[u++]=t,c[t]=v[t]=1;p<u;p++)
    	for(k=o[p],i=0;i<w[k];i++)
    		if(!v[g[k][i]])
        		l=g[k][i],o[u++]=l,c[l]=c[k]+1,v[l]=1,d=c[l];
}
int main() 
{
    freopen("darb.in","r",stdin),freopen("darb.out","w",stdout),scanf("%d",&n);
    for(i=0;i<n-1;i++)
        scanf("%d%d",&a[i],&b[i]),w[a[i]]++,w[b[i]]++;
    for(i=1;i<=n;w[i++]=0)
        g[i]=new int[w[i]];
    for(i=0;i<n-1;i++)
        g[a[i]][w[a[i]]++]=b[i],g[b[i]][w[b[i]]++]=a[i];
    B(1),B(l),printf("%d",d);
}