[이코테]-위상정렬

var obj = {
 
}

var obj_length = Array.from({ length: 8 }, () => 0);

const arr = [
 [1, 2],
 [1, 5],
 [2, 3],
 [2, 6],
 [3, 4],
 [4, 7],
 [5, 6],
 [6,4]

]
var quq = [1];


for (var i = 0; i < arr.length; i++) {

 obj_length[arr[i][1]] += 1;

 if ((Object.keys(obj).includes(arr[i][0].toString())) == false) {

  obj[arr[i][0]] = [arr[i][1]];
 
 
 }

 else {
  obj[arr[i][0]].push(arr[i][1]);
 }

}



console.log(obj)


var count=0
while (quq.length>0) {
 
 var first = quq.shift();
 // unshift/ shift 개념 헷갈리지말자..^^
console.log(first)


  if(obj[first]){
   for (var i = 0; i < obj[first].length; i++) {
    var push_obj = obj[first];
    //여기서 에러 났음//
    obj_length[push_obj[i]] -= 1;
    if (obj_length[push_obj[i]] == 0) {
     quq.push(push_obj[i]);
     console.log(quq)
    }
   
   }
  }
  
 
}

//console.log(obj_length)