Java开发学习 Java数组操作工具

import java.util.Arrays; import java.util.List; import java.util.Map; import java.util.Random; import java.util.TreeMap;   public class MyArrayUtils {           public static int[] swap(int[] ints, int x, int y) {     int temp = ints[x];     ints[x] = ints[y];     ints[y] = temp;     return ints;   }       public static int[] bubbleSort(int[] source) {          for (int i = source.length - 1; i>0 ; i--) {        for (int j = 0; j < i; j++) {          if (source[j] > source[j + 1]) {            swap(source, j, j + 1);         }       }     }     return source;   }       public static int[] selectSort(int[] source) {     for (int i = 0; i < source.length; i++) {       for (int j = i + 1; j < source.length; j++) {         if (source[i] > source[j]) {           swap(source, i, j);         }       }     }     return source;   }       public static int[] insertSort(int[] source) {      for (int i = 1; i < source.length; i++) {       for (int j = i; (j > 0) && (source[j] < source[j - 1]); j--) {         swap(source, j, j - 1);       }     }     return source;   }       public static int[] quickSort(int[] source) {     return qsort(source, 0, source.length - 1);   }       private static int[] qsort(int source[], int low, int high) {     int i, j, x;     if (low < high) {       i = low;       j = high;       x = source[i];       while (i < j) {         while (i < j && source[j] > x) {           j--;         }         if (i < j) {           source[i] = source[j];           i++;         }         while (i < j && source[i] < x) {           i++;         }         if (i < j) {           source[j] = source[i];           j--;         }       }       source[i] = x;       qsort(source, low, i - 1);       qsort(source, i + 1, high);     }     return source;   }    // /////////////////////////////////////////////   // 排序算法结束   // ////////////////////////////////////////////      public static int[] binarySearch(int[] source) {     int i,j;     int low, high, mid;     int temp;     for (i = 0; i < source.length; i++) {       temp=source[i];       low=0;       high=i-1;       while (low <= high) {         mid = (low + high)/2;         if (source[mid]>temp) {           high=mid-1;         } else {           low = mid + 1;         }       }       for (j= i-1; j>high;j--)          source[j+1]=source[j];       source[high+1]=temp;     }     return source;   }       public static int[] reverse(int[] source) {     int length = source.length;     int temp = 0;     for (int i = 0; i < length >> 1; i++) {       temp = source[i];       source[i] = source[length - 1 - i];       source[length - 1 - i] = temp;     }     return source;   }       public static int[] insert(int[] array, int index, int insertNumber) {     if (array == null || array.length == 0) {       throw new IllegalArgumentException();     }     if (index - 1 > array.length || index <= 0) {       throw new IllegalArgumentException();     }     int[] dest = new int[array.length + 1];     System.arraycopy(array, 0, dest, 0, index - 1);     dest[index - 1] = insertNumber;     System.arraycopy(array, index - 1, dest, index, dest.length - index);     return dest;   }       public static int[] remove(int[] array, int index) {     if (array == null || array.length == 0) {       throw new IllegalArgumentException();     }     if (index > array.length || index <= 0) {       throw new IllegalArgumentException();     }     int[] dest = new int[array.length - 1];     System.arraycopy(array, 0, dest, 0, index - 1);     System.arraycopy(array, index, dest, index - 1, array.length - index);     return dest;   }       public static int[] merge(int[] array1, int[] array2) {     int[] dest = new int[array1.length + array2.length];     System.arraycopy(array1, 0, dest, 0, array1.length);     System.arraycopy(array2, 0, dest, array1.length, array2.length);     return dest;   }       public static int[] offsetArray(int[] array, int offset) {     int length = array.length;     int moveLength = length - offset;     int[] temp = Arrays.copyOfRange(array, moveLength, length);     System.arraycopy(array, 0, array, offset, moveLength);     System.arraycopy(temp, 0, array, 0, offset);     return array;   }       public static List shuffle(List list) {     java.util.Collections.shuffle(list);     return list;   }       public int[] shuffle(int[] array) {     Random random = new Random();     for (int index = array.length - 1; index >= 0; index--) {       // 从0到index处之间随机取一个值，跟index处的元素交换       exchange(array, random.nextInt(index + 1), index);     }     return array;   }    // 交换位置   private void exchange(int[] array, int p1, int p2) {     int temp = array[p1];     array[p1] = array[p2];     array[p2] = temp;   }       private static List<Integer> mergeByList(int[] a, int[] b) {     // 用于返回的新数组，长度可能不为a,b数组之和，因为可能有重复的数字需要去掉     List<Integer> c = new ArrayList<Integer>();     // a数组下标     int aIndex = 0;     // b数组下标     int bIndex = 0;     // 对a、b两数组的值进行比较，并将小的值加到c，并将该数组下标+1，     // 如果相等，则将其任意一个加到c，两数组下标均+1     // 如果下标超出该数组长度，则退出循环     while (true) {       if (aIndex > a.length - 1 || bIndex > b.length - 1) {         break;       }       if (a[aIndex] < b[bIndex]) {         c.add(a[aIndex]);         aIndex++;       } else if (a[aIndex] > b[bIndex]) {         c.add(b[bIndex]);         bIndex++;       } else {         c.add(a[aIndex]);         aIndex++;         bIndex++;       }     }     // 将没有超出数组下标的数组其余全部加到数组c中     // 如果a数组还有数字没有处理     if (aIndex <= a.length - 1) {       for (int i = aIndex; i <= a.length - 1; i++) {         c.add(a[i]);       }       // 如果b数组中还有数字没有处理     } else if (bIndex <= b.length - 1) {       for (int i = bIndex; i <= b.length - 1; i++) {         c.add(b[i]);       }     }     return c;   }       private static int[] mergeByArray(int[] a, int[] b) {     int[] c = new int[a.length + b.length];      int i = 0, j = 0, k = 0;      while (i < a.length && j < b.length) {       if (a[i] <= b[j]) {         if (a[i] == b[j]) {           j++;         } else {           c[k] = a[i];           i++;           k++;         }       } else {         c[k] = b[j];         j++;         k++;       }     }     while (i < a.length) {       c[k] = a[i];       k++;       i++;     }     while (j < b.length) {       c[k] = b[j];       j++;       k++;     }     return c;   }       private static Map<Integer, Integer> mergeByTreeMap(int[] a, int[] b) {     Map<Integer, Integer> map = new TreeMap<Integer, Integer>();     for (int i = 0; i < a.length; i++) {       map.put(a[i], a[i]);     }     for (int i = 0; i < b.length; i++) {       map.put(b[i], b[i]);     }     return map;   }       public static String print(int[] array) {     StringBuffer sb = new StringBuffer();     for (int i = 0; i < array.length; i++) {       sb.append("," + array[i]);     }     System.out.println("\n"+sb.toString().substring(1));     return sb.toString().substring(1);   } }