Java-ForkJoin/MergeSort堆栈溢出

我正在使用ForkJoin框架实现一个合并排序/插入排序解决方案。但是，我得到了一个stackoverflow错误，似乎无法跟踪问题发生的位置。该解决方案旨在对1-10000000之间的一系列随机值进行排序。对于从0到100的范围，我使用插入排序，对于范围更大的范围，我使用合并排序

主要方法：

class Assignment3 {
  public static void main(String[] args) {              
    long startTime1 = System.currentTimeMillis();
    int S = 10000000;
    int d[] = new int[S];

    for(int j=0;j<d.length;j++) {
        d[j] = (int)(Math.random()*10000);
    }

    ForkJoinPool fjpool = new ForkJoinPool();
    // Array, lb, ub
    fjpool.invoke(new Ass3Q2(d,0,d.length));

    long endTime1 = System.currentTimeMillis();
    long runningTime1 = endTime1 - startTime1;
    System.out.println(runningTime1+" millisecs ("+(runningTime1/1000.0)+")");

    boolean sorted = true;
    for(int i=0;i<d.length-1;i++) {
        if(d[i] > d[i+1]) {
            sorted = false;
        }
    }
    System.out.println("Sorted List: "+sorted);
   }
 }

---

mergeSort

使用相同的参数调用自身：

mergeSort（a，l，u）

（如果我们输入

if

），这就是stackoverflow错误的原因

static void mergeSort(int a[], int l, int u) {
    if(l+1 < u) {
        int mid = (l+u)/2;
        mergeSort(a,l,u); // this call is most likely unwanted
        mergeSort(a,mid,u);
        merge(a,l,mid,u);
    }
}

静态void合并排序（int a[]，int l，int u）{
如果（l+1

发布堆栈跟踪。“你到底从哪里得到这么多？”埃德哈内德抱歉，我已经更新了操作

Exception in thread "main" java.lang.StackOverflowError
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at java.util.concurrent.ForkJoinTask.getThrowableException(Unknown Source)
at java.util.concurrent.ForkJoinTask.reportResult(Unknown Source)
at java.util.concurrent.ForkJoinTask.join(Unknown Source)
at java.util.concurrent.ForkJoinPool.invoke(Unknown Source)
at Assignment3.main(Assignment3.java:71)
Caused by: java.lang.StackOverflowError
at Ass3Q2.mergeSort(Assignment3.java:150)
at Ass3Q2.mergeSort(Assignment3.java:150)
at Ass3Q2.mergeSort(Assignment3.java:150)
at Ass3Q2.mergeSort(Assignment3.java:150)
at Ass3Q2.mergeSort(Assignment3.java:150)
at Ass3Q2.mergeSort(Assignment3.java:150)

static void mergeSort(int a[], int l, int u) {
    if(l+1 < u) {
        int mid = (l+u)/2;
        mergeSort(a,l,u); // this call is most likely unwanted
        mergeSort(a,mid,u);
        merge(a,l,mid,u);
    }
}