java 归并排序 自己写
package endual.xier.writeagain;
public class Darray {
private long[] theArray ;
private int nElems ;
public Darray(int max) {//构造数组
this.theArray = new long[max] ;
this.nElems = 0 ;
}
public void insert(long value) { //插入数据
this.theArray[this.nElems] = value ;
this.nElems++ ;
}
public void display() { //显示数组
for (long value :this.theArray) {
System.out.println(value);
}
}
public void mergeSort() {
long[] workSpace = new long[this.nElems] ;
recMergeSort(workSpace, 0, this.nElems-1) ;
}
private void recMergeSort(long[] workSpace, int lowerBound, int upperBound) {
if (lowerBound == upperBound) {
return ;
}
else {
int mid = (lowerBound + upperBound) / 2 ; //取到一个枢纽的值
recMergeSort(workSpace, lowerBound, mid) ;
recMergeSort(workSpace, mid+1, upperBound) ;
//排列他们
merge(workSpace, lowerBound, mid+1, upperBound) ;
}//end else
}
private void merge(long[] workSpace, int lowPtr, //用这个数组将数组的两半归并成一个有序的数组。
int highPtr, int upperBound) {
// TODO Auto-generated method stub
int j = 0 ;
int lowerBound = lowPtr ;
int mid = highPtr - 1 ;
int n = upperBound - lowerBound - 1 ;
while (lowPtr <= mid && highPtr <= upperBound) { //值到两个数组的其中一个用完了
if (this.theArray[lowPtr] < this.theArray[highPtr]) {
workSpace[j] = this.theArray[lowPtr] ; //将小的那个放入到工作的空间中去
j++ ; //工作的空间加1
lowPtr++ ; //最小的那个也加一
}else if (this.theArray[lowPtr] >= this.theArray[highPtr]) {
workSpace[j++] = this.theArray[highPtr++] ;
}
} // end while1
while (lowPtr <= mid) {
workSpace[j++] = this.theArray[lowPtr++] ; //直接复制进去 这两wihlt值能只执行一个的
}
while (highPtr <= upperBound) {
workSpace[j++] = this.theArray[highPtr++] ;//直接复制进去 这两wihlt值能只执行一个的
}
for (j = 0; j < n; j++) {
this.theArray[lowerBound+j] = workSpace[j] ; //进行复制
}
} //end
}
package endual.xier.writeagain;
public class MergeSortApp {
public static void main(String[] args) {
Darray da = new Darray(100) ;
for (int i = 0; i < 100; i++) {
long value = (long) (Math.random() * 10000) ;
da.insert(value) ;
}
da.display() ;
System.out.println("-----------------------------");
da.mergeSort() ;
da.display() ;
}
}
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我昏了，这个居然弄不出来哪里有错误啊，天煞的。