java 归并排序的实例详解

/**  * 归并排序  *  * @param ts  */ @SuppressWarnings("unchecked") public static <T extends Comparable<? super T>> void mergeSort(T[] ts) {    // 辅助空间   T[] tempArray = (T[]) new Comparable[ts.length];    mergeSort(ts, tempArray, 0, ts.length - 1); }  /**  * 递归  */ private static <T extends Comparable<? super T>> void mergeSort(T[] ts, T[] tempArray, int left, int right) {    if (left < right) {      int center = (left + right) / 2;      mergeSort(ts, tempArray, left, center);      mergeSort(ts, tempArray, center + 1, right);      // 左右合并     merge(ts, tempArray, left, center + 1, right);    }  }  /**  * 合并  */ private static <T extends Comparable<? super T>> void merge(T[] ts, T[] tempArray, int leftPos, int rightPos, int rightEnd) {   int leftEnd = rightPos - 1;   int temPos = leftPos;   int numElements = rightEnd - leftPos + 1;    while (leftPos <= leftEnd && rightPos <= rightEnd)     //比较放到辅助空间     if (ts[leftPos].compareTo(ts[rightPos]) <= 0)       tempArray[temPos++] = ts[leftPos++];     else       tempArray[temPos++] = ts[rightPos++];    while (leftPos <= leftEnd)     tempArray[temPos++] = ts[leftPos++];    while (rightPos <= rightEnd)     tempArray[temPos++] = ts[rightPos++];    //考回原数组,此处最好用System.arraycopy优化   for (int i = 0; i < numElements; i++, rightEnd--)     ts[rightEnd] = tempArray[rightEnd]; }