Byte jitter front end face questions two

1, multi-dimensional arrays flat. Source array [[0], [2,3,4], 1, [1, [2,3]]], the output [0,2,3,4,1,1,2,3]

{// determines whether a current array subarray
         function hasChildArray (ARR) {
           return arr.some (Element => {
             IF (Array.isArray (Element)) { 
              has = to true ;
               return  to true ; 
            } 
          }); 
        } 
        the let sourceArr = [[0], [2,. 3,. 4],. 1, [. 1, [2,. 3 ]]]; 
        the let Result = []; 
　　　　　// recursive 
        ( function doFunc (ARR) {
           IF (hasChildArray (ARR)) {
             for (the let I = 0, L = arr.length; I <L; I ++) {
              if (typeof arr[i] == "number") {
                result.push(arr[i]);
              } else if (Array.isArray(arr[i])) {
                doFunc(arr[i]);
              }
            }
          } else {
            result=result.concat(arr);
          }
        })(sourceArr);
        console.log(result);
      }

 

2, binary Tree, determines whether there is a complete path, and the value for the target, a path on which the Boolean output nodes