Array exercises
\1. Use bubble sort to realize the following array sorting from small to large.
int[] arr = new int[]{34,5,22,-98,6,-76,0,-3};
\2. How to reverse the above array. Please code implementation
\3. Copy the above array to get a new array
\4. Use linear search to find whether 22 exists from the above array. Exist, return the index of the location. If it does not exist, a prompt message will be output.
\5. What are the common exceptions in the array? Please give an example
package com.oop.Demo07;
import java.util.Arrays;
public class Demo01 {
public static void main(String[] args) {
// 1. 使用冒泡排序，实现如下的数组从小到大排序。
int[] arr = new int[]{34,5,22,-98,6,-76,0,-3};
//通过遍历比较大小交换两个数的位置
for (int i = 0; i < arr.length-1; i++) {
boolean flag = true;
for (int j = 0; j < arr.length-1-i; j++) {
if (arr[j] > arr[j+1]) {
int temp = arr[j];
arr[j] = arr[j+1];
arr[j+1] = temp;
flag = false;
}
}
}
//输出数组
for (int i = 0; i < arr.length; i++) {
System.out.print(arr[i]+"\t");
}
System.out.println();
// 2. 如何反转上面的数组。请代码实现
//确定第一个数和最后一个数 i < j 不然会导致赋值重复
for (int i = 0,j = arr.length-1; i < j; i++,j--) {
//通过temp和交换
int temp = arr[i];
arr[i] = arr[j];
arr[j] = temp;
}
for (int i = 0; i < arr.length; i++) {
System.out.print(arr[i]+"\t");
}
System.out.println();
// 3. 复制上述数组，得到一个新的数组
int[] arr2 = new int[arr.length];
for (int i = 0; i < arr.length; i++) {
arr2[i] = arr[i];
}
System.out.println(Arrays.toString(arr2));
// 4. 使用线性查找，从上述数组中查找22是否存在。存在，返回所在位置的索引。不存在，输出提示信息。
int[] arr3 = new int[]{-98,-76,-3,0,5,6,22,34};//需要排好序的数组
//定义首位，末位，和需要查找的数
int dest = 22;
int first = 0;
int end = arr3.length-1;
//布尔值判断
boolean flag = true;
while (first <= end){
//定义一个中间变量
int mid = (first + end) / 2;
if(dest == arr3[mid]){
System.out.println("找到了元素的位置"+mid);
flag = false;
break;
//首位比中间位小
}else if(dest < arr3[mid]){
end = mid - 1; //最后一位中间值减一
}else{
first = mid + 1;
}
}
if(flag) {
System.out.println("没有找到");
}
// 5. 数组中常见的异常有哪些？请举例说明
//空指针异常
//越界
}
}