js归并排序

function merge(left,right){var tmp=[];while(left.length&&right.length){if(left[0]<right[0]){tmp.push(left.shift());}else{tmp.push(right.shift());}}return tmp.concat(left,right);}function mergeSort(arr){if(arr.length==1){return arr;}var mid=Math.floor(arr.length/2);var left=arr.slice(0,mid);var right=arr.slice(mid);return merge(mergeSort(left),mergeSort(right));}