我用Java编写的合并排序程序不工作?

我用Java编写的合并排序程序不工作?,java,data-structures,mergesort,Java,Data Structures,Mergesort,我试图创建我的简单合并排序程序,该程序完全是用Java编写的,试图进行排序。请告诉我,这里怎么了 mergeSort.java: import java.util.Arrays; public class MyProgram { public static void main(String[] args){ int[] list = {2, 5, 6, 7, 52, 64, 22, 10, 11, 14, 17, 18, 19}; System.ou

我试图创建我的简单合并排序程序,该程序完全是用Java编写的,试图进行排序。请告诉我,这里怎么了

mergeSort.java:

import java.util.Arrays;

public class MyProgram {
    public static void main(String[] args){

        int[] list = {2, 5, 6, 7, 52, 64, 22, 10, 11, 14, 17, 18, 19};

        System.out.println("\t**BEFORE MERGE SORT**");
        System.out.println(Arrays.toString(list));

        mergeSort(list);

        System.out.println("\t**AFTER MERGE SORT**");
        System.out.println(Arrays.toString(list));
    }

    private static void mergeSort(int[] array){
        if(array.length > 1){
            int[] left = leftList(array);
            int[] right = rightList(array);

            mergeSort(left);
            mergeSort(right);

            //Merging the sorted half into equal parts.
            merge(array, left, right);
        }
    }

    private static int[] leftList(int[] array){
        int size = array.length/2;
        int left[] = new int[size];

        for(int i=0; i<size; i++){
            left[i] = array[i];
        }
        return left;
    }

    private static int[] rightList(int[] array){
        int size1 = array.length/2;
        int size2 = array.length - size1;
        int right[] = new int[size2];

        for(int i=0; i<size2; i++){
            right[i] = array[i+size1];
        }
        return right;
    }

    private static void merge(int[] result, int[] left, int[] right){
        int i1 = 0;
        int i2 = 0;

        for(int i=0; i<result.length; i++){
            if(i2>=right.length || (i1 < left.length && left[i1] <= right[i2])){
                result[i1] = left[i1];
                i1++;
            }
            else{
                result[i2] = left[i2];
                i2++;
            }
        }
    }
}

我们将不胜感激

尝试合并时,您没有足够的索引检查。在进行比较时,需要确保右索引和左索引都在数组的适当范围内(小于数组的大小)。如果其中一个索引不在合适的范围内,那么我们就知道该数组已经完成,我们不必再进行任何比较,因为我们只需将另一个数组中的剩余数字相加。试着这样做:

private static void merge(int[] result, int[] left, int[] right){
    int i1 = 0; //left index
    int i2 = 0; //right index
    for (int i=0; i<result.length; i++){
        if (i1<left.length && i2<right.length){ //We have something in both lists
            if (left[i1]<=right[i2]){  //Add from left
                result[i] = left[i1];
                i1++;
            }else{ //Add from right
                result[i] = right[i2];
                i2++;
            }
        }
        //If we get to here we know one list is empty
        //We need to figure out which one is empty
        else if (i1<left.length){//Right is empty
            result[i] = left[i1]; //Add from left
            i1++;
        }else{ //Left is empty
            result[i] = right[i2]; //Add from right
            i2++;
        }
    }
}
私有静态无效合并(int[]结果,int[]左,int[]右){
int i1=0;//左索引
int i2=0;//右索引

对于(int i=0;i在
merge
方法的末尾:

result[i2] = left[i2];
您正在索引
i2
处访问数组
left
,但该索引用于访问数组
right
。将其替换为
result[i2]=right[i2];
如果使用清晰的变量名,您自己就会看到这个错误


但是-您的mergesort仍然不起作用,但至少解决了
ArrayIndexOutOfBoundsException
,-)

哪一行是第63行?我同意变量名称。即使按字面上的意思将它们命名为rightIndex和leftIndex,代码的可读性也会大大提高。
result[i2] = left[i2];