算法-归并排序

public class Recursion {
@Resource
private Recursion recursion;
public void mergeSort(int[] arr) {//数据接口
    int[] temp = new int[arr.length];
    recursion.mergeSort(arr,0,arr.length-1,temp);
}
public void mergeSort(int[] arr, int left, int right, int[] temp) {
    if (left < right) {
        int mid = (left + right) / 2;
        //向左递归分解
        mergeSort(arr, left, mid, temp);
        //向右递归分解
        mergeSort(arr, mid + 1, right, temp);
        merge(arr, left, mid, right, temp);
    }
}


private  void merge(int[] arr, int left, int mid, int right, int[] temp) {
    int i = left;//左侧序列初始化索引
    int j = mid+1;//右侧序列初始化索引
    int t = 0;//temp 当前索引
    while (i <= mid && j <=right){
        if(arr[i] < arr[j]){
            temp[t] = arr[i];
            t++;
            i++;
        }else{
            temp[t] = arr[j];
            t++;
            j++;
        }
        while (i <= mid){
            temp[t] = arr[i];
            t++;
            i++;
        }
        while (j <= mid){
            temp[t] = arr[j];
            t++;
            j++;
        }
        t= 0;
        int tempLeft = left;
        while (tempLeft <= right){
            arr[tempLeft] = temp[t];
            tempLeft += 1;
        }
    }
}

}