这是关于SE基础语法的相关介绍，适合初学者参考使用 Java学习资料

import java.util.*; /** * Describe:排序的相关知识 * User:lenovo * Date:2023-01-29 * Time:15:59 */ class Sort { //基数排序,这里我们只考虑正数的情况。 public static void radixSort(int[] array) { int max = array[0]; for (int i = 0; i < array.length; i++) { if(max < array[i]) { max = array[i]; } } int maxPlace = 1; while(!(max <=9 && max >= 0)) { max /= 10; maxPlace++; } Queue<Integer> q0 = new LinkedList<>(); Queue<Integer> q1 = new LinkedList<>(); Queue<Integer> q2 = new LinkedList<>(); Queue<Integer> q3 = new LinkedList<>(); Queue<Integer> q4 = new LinkedList<>(); Queue<Integer> q5 = new LinkedList<>(); Queue<Integer> q6 = new LinkedList<>(); Queue<Integer> q7 = new LinkedList<>(); Queue<Integer> q8 = new LinkedList<>(); Queue<Integer> q9 = new LinkedList<>(); int place = 1; while(place <= maxPlace) { for (int i = 0; i < array.length; i++) { int key = array[i] % (int)(Math.pow(10, place)); int tmpPlace = place; while(--tmpPlace > 0) { key = key / 10; } switch (key) { case 0: q0.offer(array[i]); break; case 1: q1.offer(array[i]); break; case 2: q2.offer(array[i]); break; case 3: q3.offer(array[i]); break; case 4: q4.offer(array[i]); break; case 5: q5.offer(array[i]); break; case 6: q6.offer(array[i]); break; case 7: q7.offer(array[i]); break; case 8: q8.offer(array[i]); break; case 9: q9.offer(array[i]); break; } } int i = 0; while(!q0.isEmpty()) { array[i++] = q0.poll(); } while(!q1.isEmpty()) { array[i++] = q1.poll(); } while(!q2.isEmpty()) { array[i++] = q2.poll(); } while(!q3.isEmpty()) { array[i++] = q3.poll(); } while(!q4.isEmpty()) { array[i++] = q4.poll(); } while(!q5.isEmpty()) { array[i++] = q5.poll(); } while(!q6.isEmpty()) { array[i++] = q6.poll(); } while(!q7.isEmpty()) { array[i++] = q7.poll(); } while(!q8.isEmpty()) { array[i++] = q8.poll(); } while(!q9.isEmpty()) { array[i++] = q9.poll(); } place++; } } //归并排序 public static void mergeSort(int[] array) { mergeSortFunc(array, 0, array.length - 1); } private static void mergeSortFunc(int[] array, int left, int right) { if(left >= right) { return; } int mid = (left + right) / 2; mergeSortFunc(array, left, mid); mergeSortFunc(array, mid + 1, right); merge(array, left, right, mid); } private static void merge(int[] array, int start, int end, int mid) { int s1 = start; int s2 = mid + 1; int[] ret = new int[end - start + 1]; int i = 0; while(s1 <= mid && s2 <= end) { if(array[s1] < array[s2]) { ret[i++] = array[s1++]; }else { ret[i++] = array[s2++]; } } while(s1 <= mid) { ret[i++] = array[s1++]; } while(s2 <= end) { ret[i++] = array[s2++]; } for (int j = 0; j < ret.length; j++) { array[j+start] = ret[j]; } } //归并排序的非递归方法。 public static void mergeSort1(int[] array) { int gap = 1; while(gap < array.length) { for (int i = 0; i < array.length; i += gap * 2) { int left = i; int mid = left + gap - 1; if(mid >= array.length) { mid = array.length - 1; } int right = mid + gap; if (right >= array.length) { right = array.length - 1; } merge(array, left, right, mid); } gap *= 2; } } //快速排序的非递归方法 public static void quickSortNonR(int[] array, int left, int right) { Stack<Integer> s = new Stack<>(); s.push(left); s.push(right); while(!s.isEmpty()) { if(left >= right) { return; } right = s.pop(); left = s.pop(); if(right - left <= 14) { insertSort(array, left, right); continue; } midThree(array, left, right); int key = partition1(array, left, right); s.push(left); s.push(key - 1); s.push(key + 1); s.push(right); } } //快速排序 public static void quickSort(int[] array) { quick(array, 0, array.length - 1); } private static void quick(int[] array, int start, int end) { //为什么取大于号，如：1，2，3，4，5，6 if(start >= end) { return; } //为了优化，我们在剩余元素不多的情况下，我们可以直接插入排序（这是数组基本有序，复杂度不会很大） if(end - start + 1 <= 14) { //直接插入排序 insertSort(array, start, end); return; } //为了优化采取三数取中法 midThree(array, start, end); //int key = partition1(array, start, end);//划分的关键元素的下标 //int key = partition2(array, start, end); int key = partition3(array, start, end); quick(array, start, key - 1); quick(array, key + 1, end); } //为了优化快速排序，我们采取三数取中法 private static void midThree(int[] array, int left, int right) { int key; int mid = (left + right) / 2; if(array[left] < array[right]) { if(array[mid] < array[left]) { key = left; }else if(array[right] < array[mid]) { key = right; }else { key = mid; } }else { if(array[left] < array[mid]) { key = left; }else if(array[right] > array[mid]) { key = right; }else { key = mid; } } int tmp = array[left]; array[left] = array[key]; array[key] = tmp; } //前后指针法 //时间复杂度：最好情况下：O(N*logN) // 最坏情况下：O(N^2) //空间复杂度：O(1) private static int partition3(int[] array, int left, int right) { int prev = left; int cur = left + 1; while(cur <= right) { while(array[cur] < array[left] && ++prev != cur) { int tmp = array[prev]; array[prev] = array[cur]; array[cur] = tmp; } cur++; }