C :

#include <stdio.h>
#include <string.h>
int isvisited[51],mat[51][51],cnt,n;
void dfs(int start){
	if (cnt>=n)
	{
		return ;
	}
	cnt++;
	isvisited[start]=1;
	printf("%d ",start);
	for (int i=0;i<n;i++)
	{
		if (!isvisited[i]&&mat[start][i]==1)
		{
			dfs(i);
		}
	}
}
int main(){
	int i,j;
//	freopen("1.txt","r",stdin);
	while (scanf("%d",&n)==1)
	{
		for (i=0;i<n;i++)
		{
			for (j=0;j<n;j++)
			{
				scanf("%d",&mat[i][j]);
			}
		}
		cnt=0;
		memset(isvisited,0,sizeof(isvisited));
		for (i=0;i<n;i++)
		{
			if (!isvisited[i])
			{
				dfs(i);
			}
		}
		printf("\n");
	}
//	fclose(stdin);
	return 0;
}

Java :

import java.util.Scanner;

public class Main {
   private static Scanner s = new Scanner(System.in) ;
   
   public static void main(String[] args) {
	   int n = s.nextInt() ;
	   int a[][] = new int[n][n] ;
	   boolean visited[] = new boolean[n] ;
	   for (int i = 0; i < a.length; i++) {
		 for (int j = 0; j < a.length; j++) {
			a[i][j] = s.nextInt() ;
		 }
	    }
	   for (int i = 0; i < visited.length; i++) {
		  a[i][i] = 1 ;
	   }
	   
	   Graph g = init(a ,visited) ;
	   deptSearch(g, 0) ;
	   System.out.println() ;
   } 
   
   public static Graph init(int a[][] , boolean visited[]){
	   Graph g = new Graph(a.length) ;
	   g.visited = visited ;
	   g.a = a ;
	   return g ;
   }
   public static void deptSearch(Graph g,int x){
	   for (int i = 0; i < g.n; i++) {
		   if(g.a[x][i] ==1&&g.visited[i]==false){
			   g.visited[i] = true ;
			   visit(i) ;
			   deptSearch(g, i) ;
		   }
	   }
   }
   public static void visit(int i){
	   System.out.print(i+" ");
   }
}

class Graph{
	int n  ;
	int a[][] = new int [n][n] ;
	boolean visited[] = new boolean[n] ;
	public Graph(int n) {
       this.n = n ;
	}
}