[力扣Hot 100------第8题--207.课程表]

这题算是DFS/BFS这块最难下手的一题了，需要多刷几遍~~

1.BFS

var canFinish = function(numCourses, prerequisites) {
    var num=numCourses;
    var arr=new Array(num).fill(0);
    for(let item of prerequisites) arr[item[0]]++;
    var queue=[];
    for(var i=0,len=arr.length;i

2.DFS

var canFinish = function(numCourses, prerequisites) {
    const num=numCourses;
    var flag=new Array(num).fill(0);
    var matrix=new Array(num);
    for(var i=0;i