排序算法-计数排序

package sort
//计数排序
//计数排序
func CountingSort(arr []int64) {
    //1.寻找最大值
    max := arr[0]
    base := arr[0]
    for _,item := range arr {
        if item > max {
            max = item
        }
        if item < base {
            base = item
        }
    }
    //2.建桶
    bucketList := make([]int64, max-base+1,max-base+1)
    for _,item := range arr {
        bucketList[item]++
    }

    //3.遍历
    index := 0
    for key,item := range bucketList {
        if item > 0 {
            var c int64
            for ;c < item;c++ {
                arr[index] = base+int64(key)
                index++
            }
        }
    }
}