JAVA mergeSort返回数组

Question

我一直有我的mergesort（）实现的问题，因为我返回一个数组，我得到mergesotrt（）中的stackoverflow错误。我的merge（）工作正常这是一个小的clippet我的整个程序有一个ArraytoString（）哪些工作正常，并打印到控制台即时通讯添加在alp im不允许更改实现类型，如基本格式必须保持 {37,27 ，43，3，9，81，10}

public static int[] merge(int[] arr1, int start, int mid, int end, int[] temp) { 

    int beginHalf1 = start; 
    int endHalf1 = mid; 
    int beginHalf2 = mid+1; 
    int endHalf2 = end; 
    //if odd its mid half of 
    int index = 0; 
    //until arraysect runs out check which is smaller and send to temp 
    while (beginHalf1 <= endHalf1 && beginHalf2 <= endHalf2){ 

    if(arr1[beginHalf1] <= arr1[beginHalf2]){ 

     temp[index] = arr1[beginHalf1]; 
     beginHalf1++; 
    }else {//>= 

     temp[index] = arr1[beginHalf2]; 
     beginHalf2++; 
    } 

    index++; 
    }//pass leftover items to array 
    if(beginHalf1>endHalf1){//right half not done 

     while (beginHalf2<=endHalf2){ 

      temp[index] = arr1[beginHalf2]; 
      beginHalf2++; 
      index++; 
     } 

    }else if(beginHalf2>endHalf2){ //left half not done 

     while (beginHalf1<=endHalf1){ 

      temp[index] = arr1[beginHalf1]; 
      beginHalf1++; 
      index++; 
     } 

    } 
    return temp; 
} 


public static int[] mergeSort(int[] arr, int start, int end, int[] temp) { 
    //arr unsorted returns sorted copy of that array 
    //idk why it doesnt run 

    if (start < end) { 

     int mid = ((start + end)/2)-1;//offset for mid for odd size 

     mergeSort(arr, start, mid, temp); 

     mergeSort(arr, mid + 1, end, temp); 

     merge(temp, start, mid, end, temp); 

    } 

    return temp;//what do i return 

} 
public static void main(String[] args) { 

    int[] arr = {37, 27, 43, 3, 9, 81, 10};//3,9,10,27,39,43 

    int length = sortedmerge.length/2-1;//-1 offset for mid 


    arrayToString(mergeSort(arr,0,arr.length,new int[arr.length])); 


} 

Answer 1

if (start < end) { 
    int mid = ((start + end)/2) - 1; //offset for mid for odd size 
    mergeSort(arr, start, mid, temp); 
    mergeSort(arr, mid + 1, end, temp); 
    merge(temp, start, mid, end, temp); 
} 

start永远不会小于mid所以你的mergeSort(arr, start, mid, temp);第一invokation似乎进入英辉循环导致计算器。