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选择排序,冒泡排序,插入排序,二分法查找...

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pull/3/head
Leo 5 years ago
parent 4e475ab638
commit e4b6b6c2a8
7 changed files with 696 additions and 0 deletions
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8
.gitignore vendored
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/out/
*.iml
.idea
.DS_Store

87
src/leo/class01/BSExist.java
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package leo.class01;
import leo.util.ArrayUtil;
import java.util.Arrays;
/**
* @author Leo
* @ClassName BSExist
* @DATE 2020/11/12 10:14 上午
* @Description 二分查找是否存在
*/
public class BSExist {
/**
* 功能描述 : 二分查找某数是否存在
* @author Leo
* @date 2020/11/12 10:36 上午
* @param arr 有序数组
* @param value
* @return boolean
*/
public static boolean exist(int[] arr, int value) {
if (arr == null || arr.length == 0) {
return false;
}
int L = 0;
int R = arr.length - 1;
int mid = 0;
while (L < R) {
//右移一位表示除以2
mid = L + ((R - L) >> 1);
if (arr[mid] == value) {
return true;
} else if (arr[mid] > value) {
R = mid - 1;
}else {
L = mid + 1;
}
}
return arr[L] == value;
}
/**
* 功能描述 : test
* @author Leo
* @date 2020/11/12 10:36 上午
* @param arr 二分查找某数是否存在
* @param value
* @return boolean
*/
public static boolean forExist(int[] arr, int value) {
for (int i : arr) {
if (i == value) {
return true;
}
}
return false;
}
public static void main(String[] args){
int maxSize = 50;
int range = 500;
int testTime = 100;
boolean succeed = true;
for (int i = 0; i < testTime; i++) {
int[] sortArr = ArrayUtil.randomSortArray(maxSize, range);
int value = (int) ((range + 1) * Math.random() - (range + 1) * Math.random());
if (exist(sortArr, value) != forExist(sortArr, value)) {
succeed = false;
ArrayUtil.printArr(sortArr);
break;
}
}
System.out.println(succeed ? "Nice!" : "Fucking Fucked!");
}
}

142
src/leo/class01/BSNear.java
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package leo.class01;
import leo.util.ArrayUtil;
/**
* @author Leo
* @ClassName BSNear
* @DATE 2020/11/12 11:18 上午
* @Description
*/
public class BSNear {
/**
* 功能描述 : 在有序数组中找出>=某个数最左侧的位置
* @author Leo
* @date 2020/11/12 3:01 下午
* @param arr
* @param value
* @return int
*/
public static int BSNearLeft(int[] arr, int value) {
if (arr == null || arr.length == 0) {
return -1;
}
int index = -1;
int L = 0;
int R = arr.length - 1;
while (L <= R) {
int mid = L + ((R - L) >> 1);
if (arr[mid] >= value) {
index = mid;
R = mid - 1;
} else {
L = mid + 1;
}
}
return index;
}
/**
* 功能描述 : 在有序数组中找出>=某个数最左侧的位置(for test)
* @author Leo
* @date 2020/11/12 3:02 下午
* @param arr
* @param value
* @return int
*/
public static int forTestBSNearLeft(int[] arr, int value) {
if (arr == null || arr.length == 0) {
return -1;
}
for (int i = 0; i < arr.length; i++) {
if (arr[i] >= value) {
return i;
}
}
return -1;
}
/**
* 功能描述 : 在有序数组中找出<=某个数最右侧的位置
* @author Leo
* @date 2020/11/12 3:05 下午
* @param arr
* @param value
* @throw
* @return int
*/
public static int BSNearRight(int[] arr, int value) {
int index = -1;
if (arr == null || arr.length == 0) {
return index;
}
int L = 0;
int R = arr.length - 1;
int mid = 0;
while (L <= R) {
mid = (L + R) >> 1;
if (arr[mid] <= value) {
index = mid;
L = mid + 1;
} else {
R = mid - 1;
}
}
return index;
}
public static int forTestBSNearRight(int[] arr, int value) {
int index = -1;
if (arr == null || arr.length == 0) {
return index;
}
for (int i = arr.length - 1; i >= 0; i--) {
if (arr[i] <= value) {
return i;
}
}
return index;
}
public static void main(String[] args){
int maxSize = 80;
int range = 800;
int testTime = 10000;
boolean success = true;
for (int i = 0; i < testTime; i++) {
int[] sortArr = ArrayUtil.randomSortArray(maxSize, range);
int value = (int) ((range + 1) * Math.random() - (range + 1) * Math.random());
final int res1 = BSNearLeft(sortArr, value);
final int res2 = forTestBSNearLeft(sortArr, value);
final int res3 = BSNearRight(sortArr, value);
final int res4 = forTestBSNearRight(sortArr, value);
if (res1 != res2) {
success = false;
ArrayUtil.printArr(sortArr);
System.out.println("BSNearLeft=" + res1);
System.out.println("forTestBSNearLeft=" + res2);
break;
}
if (res3 != res4) {
success = false;
ArrayUtil.printArr(sortArr);
System.out.println("BSNearRight=" + res3);
System.out.println("forTestBSNearRight=" + res4);
break;
}
}
System.out.println(success ? "Nice!!" : "Fucking Fucked!");
}
}

95
src/leo/class01/BubbleSort.java
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package leo.class01;
import leo.util.ArrayUtil;
import java.util.Arrays;
/**
* @author Leo
* @ClassName BubbleSort
* @DATE 2020/11/11 9:05 下午
* @Description 冒泡算法
*/
public class BubbleSort {
/**
* 功能描述 : 冒泡算法 O(n²)
* @author Leo
* @date 2020/11/11 10:09 下午
* @param arr
* @return void
*/
public static void bubbleSort(int[] arr) {
if (arr == null || arr.length < 2) {
return;
}
for (int i = arr.length-1; i > 0; i--) {
for (int j = 0; j < i; j++) {
if (arr[j] > arr[j + 1]) {
swap(arr, j, j + 1);
}
}
}
}
public static void bubbleSort2(int[] arr) {
if (arr == null || arr.length < 2) {
return;
}
for (int i = arr.length - 1; i > 0; i--) {
for (int j = 0; j < i; j++) {
if (arr[j] > arr[j + 1]) {
swap(arr, j, j + 1);
}
}
}
}
/**
* 功能描述 : 交换
* @author Leo
* @date 2020/11/11 6:34 下午
* @param arr
* @param i
* @param j
* @return void
*/
private static void swap(int[] arr, int i, int j) {
if (arr == null ||
arr.length <= i ||
arr.length <= j ||
i == j) {
return;
}
arr[i] = arr[i] ^ arr[j];
arr[j] = arr[i] ^ arr[j];
arr[i] = arr[i] ^ arr[j];
}
public static void main(String[] args){
int maxSize = 500;
int range = 20;
int testOfTime = 100000;
boolean succeed = true;
for (int i = 0; i < testOfTime; i++) {
int[] arr = ArrayUtil.randomArray(maxSize, range);
int[] anotherArr = ArrayUtil.copyArray(arr);
bubbleSort2(arr);
Arrays.sort(anotherArr);
if (!ArrayUtil.isEqual(arr, anotherArr)) {
succeed = false;
ArrayUtil.printArr(arr, "arr");
ArrayUtil.printArr(anotherArr, "anotherArr");
break;
}
}
System.out.println(succeed ? "Nice!" : "Fucking fucked!");
}
}

75
src/leo/class01/InsertionSort.java
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package leo.class01;
import leo.util.ArrayUtil;
import java.util.Arrays;
import java.util.jar.JarEntry;
/**
* @author Leo
* @ClassName InsertionSort
* @DATE 2020/11/12 9:21 上午
* @Description
*/
public class InsertionSort {
/**
* 功能描述 : 插入排序
* @author Leo
* @date 2020/11/12 9:58 上午
* @param arr
* @throw
* @return void
*/
public static void insertionSort(int[] arr) {
if (arr == null || arr.length < 2) {
return;
}
for (int i = 1; i < arr.length; i++) {
for (int j = i - 1; j >= 0 && arr[j] > arr[j + 1]; j--) {
swap(arr, j, j + 1);
}
}
}
private static void swap(int[] arr, int i, int j) {
if (arr == null
|| arr.length < 2
|| arr.length <= i
|| arr.length <= j) {
return;
}
arr[i] = arr[i] ^ arr[j];
arr[j] = arr[i] ^ arr[j];
arr[i] = arr[i] ^ arr[j];
}
public static void main(String[] args){
int maxSize = 50;
int range = 80;
int testOfTime = 100000;
boolean succeed = true;
for (int i = 0; i < testOfTime; i++) {
int[] arr = ArrayUtil.randomArray(maxSize, range);
int[] anotherArr = ArrayUtil.copyArray(arr);
insertionSort(arr);
Arrays.sort(anotherArr);
if (!ArrayUtil.isEqual(arr, anotherArr)) {
succeed = false;
ArrayUtil.printArr(arr, "arr");
ArrayUtil.printArr(anotherArr, "anotherArr");
break;
}
}
System.out.println(succeed ? "Nice!" : "Fucking fucked!");
}
}

130
src/leo/class01/SelectionSort.java
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package leo.class01;
import leo.util.ArrayUtil;
import java.util.Arrays;
/**
* @author Leo
* @ClassName SelectionSort
* @DATE 2020/11/11 6:24 下午
* @Description 选择排序
*/
public class SelectionSort {
/**
* 功能描述 : 选择排序 O(n²)
* @author Leo
* @date 2020/11/11 6:38 下午
* @param arr
* @return void
*/
public static void selectionSort(int[] arr) {
if (arr == null || arr.length < 2) {
return;
}
for (int i = 0; i < arr.length-1; i++) {
int minIndex = i;
for (int j = i + 1; j < arr.length; j++) {
minIndex = arr[j] > arr[minIndex] ? minIndex : j;
}
swap(arr, i, minIndex);
}
}
/**
* 功能描述 :
* @author Leo
* @date 2020/11/11 9:15 下午
* @param arr
* @return void
*/
public static void selectionSort2(int[] arr) {
if (arr == null || arr.length < 2) {
return;
}
for (int i = 0; i < arr.length-1; i++) {
int minIndex = i;
for (int j = i + 1; j < arr.length; j++) {
minIndex = arr[j] < arr[minIndex] ? j : minIndex;
}
swap(arr, i, minIndex);
}
}
public static void selectionSort3(int[] arr) {
if (arr == null || arr.length < 2) {
return;
}
for (int i = 0; i < arr.length - 1; i++) {
int minIndex = i;
for (int j = i+1; j < arr.length; j++) {
minIndex = arr[j] > arr[minIndex] ? minIndex : j;
}
swap(arr, i, minIndex);
}
}
public static void selectionSort4(int[] arr) {
if (arr == null || arr.length < 2) {
return;
}
for (int i = 0; i < arr.length - 1; i++) {
int minIndex = i;
for (int j = i + 1; j < arr.length; j++) {
minIndex = arr[j] < arr[minIndex] ? j : minIndex;
}
swap(arr, i, minIndex);
}
}
/**
* 功能描述 : 交换
* @author Leo
* @date 2020/11/11 6:34 下午
* @param arr
* @param i
* @param j
* @return void
*/
private static void swap(int[] arr, int i, int j) {
if (arr == null ||
arr.length <= i ||
arr.length <= j ||
i == j) {
return;
}
arr[j] = arr[j] ^ arr[i];
arr[i] = arr[j] ^ arr[i];
arr[j] = arr[j] ^ arr[i];
}
public static void main(String[] args){
int maxSize = 100;
int range = 50;
int testOfTime = 100000;
boolean succeed = true;
for (int i = 0; i < testOfTime; i++) {
int[] arr = ArrayUtil.randomArray(maxSize, range);
int[] anotherArr = ArrayUtil.copyArray(arr);
selectionSort4(arr);
Arrays.sort(anotherArr);
if (!ArrayUtil.isEqual(arr, anotherArr)) {
succeed = false;
ArrayUtil.printArr(arr, "arr");
ArrayUtil.printArr(anotherArr, "anotherArr");
break;
}
}
System.out.println(succeed ? "Nice!" : "Fucking fucked!");
}
}

159
src/leo/util/ArrayUtil.java
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package leo.util;
import java.util.Arrays;
/**
* @author Leo
* @ClassName util
* @DATE 2020/11/11 6:55 下午
* @Description 对数器工具
*/
public class ArrayUtil {
/**
* 功能描述 : 随机生成数组
* @author Leo
* @date 2020/11/11 6:57 下午
* @param maxSize 数组最大值
* @param range 数组元素范围
* @return int[]
*/
public static int[] randomArray(int maxSize, int range) {
int[] arr = new int[(int) ((maxSize + 1) * Math.random())];
for (int i = 0; i < arr.length; i++) {
arr[i] = (int) ((range + 1) * Math.random()- (range * Math.random())) ;
}
return arr;
}
/**
* 功能描述 : 生成随机有序数组
* @author Leo
* @date 2020/11/12 10:42 上午
* @param maxSize
* @param range
* @return int[]
*/
public static int[] randomSortArray(int maxSize, int range) {
int[] arr = randomArray(maxSize, range);
Arrays.sort(arr);
return arr;
}
/**
* 功能描述 : 复制数组
* @author Leo
* @date 2020/11/11 6:57 下午
* @param arr
* @return int[]
*/
public static int[] copyArray(int[] arr) {
int[] newArr = new int[arr.length];
if (arr != null && arr.length > 0) {
for (int i = 0; i < arr.length; i++) {
newArr[i] = arr[i];
}
return newArr;
}
return newArr ;
}
/**
* 功能描述 : 判断数组是否一样
* @author Leo
* @date 2020/11/11 7:20 下午
* @param arr1
* @param arr2
* @return boolean
*/
public static boolean isEqual(int[] arr1, int[] arr2) {
return isEqual(arr1, arr2, false);
}
/**
* 功能描述 : 判断数组是否一样并打印
* @author Leo
* @date 2020/11/11 7:21 下午
* @param arr1
* @param arr2
* @return boolean
*/
public static boolean isEqualAndPrint(int[] arr1, int[] arr2) {
return isEqual(arr1, arr2, true);
}
/**
* 功能描述 : 判断数组
* @author Leo
* @date 2020/11/11 7:15 下午
* @param arr1
* @param arr2
* @param printJudge 是否打印
* @return boolean
*/
private static boolean isEqual(int[] arr1, int[] arr2,boolean printJudge) {
if (printJudge) {
printArr(arr1, "arr1");
printArr(arr2, "arr2");
}
if (arr1 == null && arr2 == null) {
return true;
}else if (arr1 == null || arr2 == null) {
return false;
}else if (arr1.length != arr2.length) {
return false;
}
for (int i = 0; i < arr1.length; i++) {
if (arr1[i] != arr2[i]) {
return false;
}
}
return true;
}
/**
* 功能描述 : 打印数组
* @author Leo
* @date 2020/11/11 7:15 下午
* @param arr
* @param arrName
* @return void
*/
public static void printArr(int[] arr, String arrName) {
StringBuffer arrStr = new StringBuffer();
arrName = arrName == null ? "arr" : arrName;
arrStr.append(" " + arrName + " = [");
if (arr == null || arr.length <= 0) {
System.out.println();
arrStr.append("]");
}
for (int i = 0; i < arr.length; i++) {
arrStr.append(" " + arr[i] + ",");
}
arrStr.substring(0, arrStr.length() - 2);
arrStr.append(" ]");
System.out.println(arrStr);
}
/**
* 功能描述 : 打印数组
* @author Leo
* @date 2020/11/12 2:17 下午
* @param arr
* @return void
*/
public static void printArr(int[] arr) {
printArr(arr, null);
}
}
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