poj2258 简单dfs The Settlers of Catan

http://poj.org/problem?id=2258

dfs 边是双向的 节点可以走多次 开个二维数组标记边 因为可以从任一节点出发所以n次dfs

#include <stdio.h>
#include<string.h>
int x[26][26],v,w,n;
void dfs(int i,int v)
{
    int j;
    for(j = 0 ; j <= n-1 ; j++)
    {
        if(x[i][j] == 1)
        {
            x[i][j] = 0;
            x[j][i] = 0;
            dfs(j,v+1);
            x[i][j] = 1;
            x[j][i] = 1;
        }
    }
    if(w<v)
    w = v;
}
int main()
{
    int m, i,j,a,b;
    while(scanf("%d%d", &n, &m)!=EOF)
    {
        if(n == 0 && m == 0)
        break;
        memset(x,0,sizeof(x));
        w = 0;
        for(i = 1 ; i <= m ; i++)
        {
            scanf("%d%d", &a, &b);
            x[a][b] = 1;
            x[b][a] = 1;
        }
        for(i = 0 ; i <= n-1 ; i++)
        {
            dfs(i,0);
        }
        printf("%d\n", w);
    }
    return 0;
}