合并排序

具体原理可看这里

javascript版本：

function merge(left, right){
var result = [];
while (left.length > 0 && right.length > 0){
if (left[0] < right[0]){
result.push(left.shift());//把最小的最先取出，放到结果集中
} else {
result.push(right.shift());
}
} return result.concat(left).concat(right);//剩下的就是合并，这样就排好序了
}
function mergeSort(array){
if (array.length == 1) {
return array;
}
var middle = Math.floor(array.length / 2),//求出中点
left = array.slice(0, middle),//分割数组
right = array.slice(middle);
return merge(mergeSort(left), mergeSort(right));//递归合并与排序
}

ruby版本：

def merge(left, right)
final = []
until left.empty? or right.empty?
final << ( left.first < right.first ? left.shift : right.shift )
end
final + left + right
end
def mergeSort(array)
return array if array.size < 2
left = array.first(array.size/2)
right = array.last(array.size - array.size/2)
merge(mergeSort(left), mergeSort(right))
end

//by 司徒正美function merge(left, right){ var result = []; while (left.length > 0 && right.length > 0){ if (left[0] < right[0]){ result.push(left.shift());//把最小的最先取出，放到结果集中 } else { result.push(right.shift()); } } return result.concat(left).concat(right);//剩下的就是合并，这样就排好序了 } function mergeSort(array){ if (array.length == 1) { return array; } var middle = Math.floor(array.length / 2),//求出中点 left = array.slice(0, middle),//分割数组 right = array.slice(middle); return merge(mergeSort(left), mergeSort(right));//递归合并与排序 }
var a = [49, 38 ,65 ,97 ,76, 13, 27]

alert(mergeSort(a))

运行代码