Array inversion learning record
package p1;
/**
* Array reverse
* @author Guozhu Zhu
* @date 2018/4/22
* @version 1.0
*
*/
public class Test12 {
public static void main(String[] args) {
int[] arr = {1, 7, 9, 2};
reverseArr1(arr);
for (int i : arr) {
System.out.println(i);
}
}
/*
* Implement 1
*/
public static void reverseArr(int[] arr) {
for (int i = 0, j = arr.length-1; i < j; i++, j--) {
int temp = arr[j];
arr[j] = arr[i];
arr[i] = temp;
}
}
/*
* Implementation 2
*/
public static void reverseArr1(int[] arr) {
for (int i = 0; i <= ((arr.length-1)/2); i++) {
int temp = arr[i];
arr[i] = arr[arr.length-1-i];
arr[arr.length-1-i] = temp;
}
}
}