-2

私はいくつかの入力に取り組まなければならないことを知っています。しかし、コードはどのようになりますか？仮定する

   public static void mergeSort(Comparable[] a, int left, int right) {
      if (right <= left) return;
      int mid = left + (right – left) / 2;
      mergeSort(a, left, mid);
      mergeSort(a, mid + 1, right);
      merge(a, left, mid, right);
   } 
   public void merge(Comparable[] a, int left, int mid,int right) {
     for (int k = left; k <= right; k++) aux[k] = a[k]; 
       int i = left; j = mid + 1;
     for (int k = left; k <= right; k++) {
       if (i > mid) a[k] = aux[j++];
       else if (j > right) a[k] = aux[i++];
       else if (less(aux[j], aux[i]) a[k] = aux[j++];
       else a[k] = aux[i++];
     }
  }

マージソート法です。

4

1 に答える 1

-1 
public class Mergesort {
  private int[] numbers;
  private int[] helper;

  private int number;

  public void sort(int[] values) {
    this.numbers = values;
    number = values.length;
    this.helper = new int[number];
    mergesort(0, number - 1);
  }

  private void mergesort(int low, int high) {
    // Check if low is smaller then high, if not then the array is sorted
    if (low < high) {
      // Get the index of the element which is in the middle
      int middle = low + (high - low) / 2;
      // Sort the left side of the array
      mergesort(low, middle);
      // Sort the right side of the array
      mergesort(middle + 1, high);
      // Combine them both
      merge(low, middle, high);
    }
  }

  private void merge(int low, int middle, int high) {

    // Copy both parts into the helper array
    for (int i = low; i <= high; i++) {
      helper[i] = numbers[i];
    }

    int i = low;
    int j = middle + 1;
    int k = low;
    // Copy the smallest values from either the left or the right side back
    // to the original array
    while (i <= middle && j <= high) {
      if (helper[i] <= helper[j]) {
        numbers[k] = helper[i];
        i++;
      } else {
        numbers[k] = helper[j];
        j++;
      }
      k++;
    }
    // Copy the rest of the left side of the array into the target array
    while (i <= middle) {
      numbers[k] = helper[i];
      k++;
      i++;
    }

  }
}

ここから並べ替えサンプルをマージ

于 2013-10-01T05:39:18.443 に答える