201507241357_《JavaScript——合并》

//merge()函数
function merge(left, right){ 
  var result = []; 
  while (left.length > 0 && right.length > 0){ 
    if (left[0] < right[0]){ 
      result.push(left.shift()); 
    } else { 
      result.push(right.shift()); 
    } 
  } 
  return result.concat(left).concat(right); 
}; 


//mergeSort()函数
function mergeSort(items){ 
  if (items.length == 1) { 
    return items; 
  } 
  var middle = Math.floor(items.length / 2), 
  left = items.slice(0, middle), 
  right = items.slice(middle); 
  return merge(mergeSort(left), mergeSort(right)); 
}; 

//test
var lArr = [2,4,7,4,2,7]; 
var rArr = [3,6,3,8,2,9]; 
var newArr = merge(lArr,rArr); 
for(var len = newArr.length,i = len;i>=0;i--){console.log(newArr[i])};  //9,2,8,7,2,4,7,3,6,4,3,2