UVA 539 SOLUTION

#include<stdio.h>
#define READ freopen("input.txt","r",stdin)
#define WRITE freopen("output.txt","w",stdout)
#define ll long long
#define MAX(a,b)  a>b?a:b
#define siz 102
using namespace std ;

int node,edge,mx,path;
int adj[50][50] ;

void dfs(int cur)
{

    for(int i = 0; i< node; i++)
    {

        if(adj[cur][i]==1)
        {
            path++;
            adj[cur][i]= 0 ;
            adj[i][cur]= 0 ;
            dfs(i);
            adj[cur][i]= 1 ;
            adj[i][cur]= 1 ;
            path--;

        }
    }
       mx = MAX(mx,path) ;
}


int main()
{

  //  READ;
    while(scanf("%d %d",&node,&edge)==2)
    {
        if(node==0 && edge==0) break ;

        for(int i = 0 ; i<32; i++)
            for(int j = 0; j<32; j++) adj[i][j] = 0 ;

        // for(int i =0 ; i<=node; i++) mark[i] = false ;
        for(int i = 0; i<edge; i++)
        {
            int u,v;
            scanf("%d %d",&u,&v);
            adj[u][v] = 1 ;
            adj[v][u] = 1 ;
        }
        int ans = 0 ;
        for(int i = 0 ; i<node; i++)
        {
            mx = 0;
            dfs(i);
            ans = MAX(ans, mx) ;
        }
        printf("%d\n",ans) ;
    }

    return 0 ;
}