java 归并排序

Posted 2021-01-10 沙漠里的小鱼

    public void mergeSort(int[] arry, int low ,int high){
        if (low < high){
            int middle = ( low +high)/2 ;
            mergeSort(arry,low,middle);
            mergeSort(arry,middle+1,high);
            sort(arry,low,middle,high);
        }
    }


    public void sort(int[] arry ,int low ,int middle ,int high){
        int[] temp = new int[high - low + 1] ;
        int i = low ;
        int j = middle +1 ;
        int index=0; ;
        while (i <= middle && j <= high){
            if(arry[i] < arry[j]){
                temp[index++] =arry[i++] ;
            }else{
                temp[index++] =arry[j++] ;
            }
        }
        while (i <= middle) {
            temp[index++] =arry[i++] ;
        }
        while (j <= high){
            temp[index++] =arry[j++] ;
        }
        for (int m= 0;m < temp.length; m++) {
            arry[low + m] = temp[m];
        }
    }