How do I convert this C++ code to java?

See more:

C++

Java

#include <iostream>
#include <queue>
#include <vector>
using namespace std;

// function to determine level of each node starting
// from x using BFS
void printLevels(vector<int> graph[], int V, int x)
{
// array to store level of each node
int level[V];
bool marked[V];

// create a queue
queue<int> que;

// enqueue element x
que.push(x);

// initialize level of source node to 0
level[x] = 0;

// marked it as visited
marked[x] = true;

// do until queue is empty
while (!que.empty()) {

// get the first element of queue
x = que.front();

// dequeue element
que.pop();

// traverse neighbors of node x
for (int i = 0; i < graph[x].size(); i++) {
// b is neighbor of node x
int b = graph[x][i];

// if b is not marked already
if (!marked[b]) {

// enqueue b in queue
que.push(b);

// level of b is level of x + 1
level[b] = level[x] + 1;

// mark b
marked[b] = true;
}
}
}

// display all nodes and their levels
cout << "Nodes"
<< " "
<< "Level" << endl;
for (int i = 0; i < V; i++)
cout << " " << i << " --> " << level[i] << endl;
}

// Dirver Code
int main()
{
// adjacency graph for tree
int V = 8;
vector<int> graph[V];

graph[0].push_back(1);
graph[0].push_back(2);
graph[1].push_back(3);
graph[1].push_back(4);
graph[1].push_back(5);
graph[2].push_back(5);
graph[2].push_back(6);
graph[6].push_back(7);

// call levels function with source as 0
printLevels(graph, V, 0);

return 0;
}

What I have tried:

package bfsjava;


public class BFSJAVA {


public static void printLevels(vector <int>[] graph, int V, int x)
{
// array to store level of each node
int[] level = new int[V];
boolean[] marked = new boolean[V];

// create a queue
queue<int> que = new queue<int>();

// enqueue element x
que.push(x);

// initialize level of source node to 0
level[x] = 0;

// marked it as visited
marked[x] = true;

// do until queue is empty
while (!que.empty())
{

// get the first element of queue
x = que.front();

// dequeue element
que.pop();

// traverse neighbors of node x
for (int i = 0; i < graph[x].size(); i++)
{
// b is neighbor of node x
int b = graph[x][i];

// if b is not marked already
if (!marked[b])
{

// enqueue b in queue
que.push(b);

// level of b is level of x + 1
level[b] = level[x] + 1;

// mark b
marked[b] = true;
}
}
}

// display all nodes and their levels
System.out.print("Nodes");
System.out.print(" ");
System.out.print("Level");
System.out.print("\n");
for (int i = 0; i < V; i++)
{
System.out.print(" ");
System.out.print(i);
System.out.print(" --> ");
System.out.print(level[i]);
System.out.print("\n");
}
}

// Dirver Code
public static int Main()
{
// adjacency graph for tree
int V = 8;
vector<int> graph[V];

graph[0].push_back(1);
graph[0].push_back(2);
graph[1].push_back(3);
graph[1].push_back(4);
graph[1].push_back(5);
graph[2].push_back(5);
graph[2].push_back(6);
graph[6].push_back(7);

// call levels function with source as 0
printLevels(graph, V, 0);

return 0;
}

}