Breadth first search.

breadthFirstSearch

function breadthFirstSearch(node){
    
    // build a queue
    var q = [];
    
    // initialize q
    q.push(node);
    
    var currentNode = null;
    
    while(q.length !== 0){
        currentNode = q.shift();
        // visit node
        console.log(currentNode.value);
        currentNode.visited = true;
        
        for (var i = 0; i < currentNode.children.length; i++){
            if (currentNode.children[i].visited === false){
                q.push(currentNode.children[i]);
            }
        }              
    }
}

// a = {value:1, visited:false, children:[]};
// b = {value:2, visited:false, children:[]};
// c = {value:3, visited:false, children:[]};
// d = {value:4, visited:false, children:[]};
// e = {value:15, visited:false, children:[]};
// f = {value:6, visited:false, children:[]};
// g = {value:7, visited:false, children:[]};
// h = {value:8, visited:false, children:[]};

// a.children.push(b);
// a.children.push(c);
// a.children.push(d);
// b.children.push(e);
// c.children.push(f);
// d.children.push(g);
// e.children.push(h);

// breathFirstSearch(a);