LeftRotateArray1Pos.java

packagegfg.Arrays;

importjava.util.Arrays;

publicclassLeftRotateArray1Pos {

publicstaticvoidmain(String[] args) {

int[] arr = { 1, 2, 3, 4, 5 };
System.out.println("original array: " + Arrays.toString(arr));

rotateLeft(arr);

System.out.println("rotated array: " + Arrays.toString(arr));

int[] arr2 = { 5, 10, 20 };
System.out.println("original array: " + Arrays.toString(arr2));

rotateLeft2(arr2);

System.out.println("rotated array: " + Arrays.toString(arr2));
 }

// O(n) time | O(1) space
publicstaticvoidrotateLeft(int[] arr) {
for (inti = 0; i < arr.length - 1; i++) {
swap(arr, i, i + 1);
 }
 }

publicstaticvoidswap(int[] arr, inta, intb) {
inttemp = arr[a];
arr[a] = arr[b];
arr[b] = temp;
 }

// without using swap - O(n) time | O(1) space
publicstaticvoidrotateLeft2(int[] arr) {
inttemp = arr[0];
for (inti = 1; i < arr.length; i++) {
arr[i - 1] = arr[i];
 }
arr[arr.length - 1] = temp;
 }
}

/* output:
original array: [1, 2, 3, 4, 5]
rotated array: [2, 3, 4, 5, 1]
original array: [5, 10, 20]
rotated array: [10, 20, 5]
 */