MoveZerosToFront.java

packagegfg.Arrays;

importjava.util.Arrays;

publicclassMoveZerosToFront {

publicstaticvoidmain(String[] args) {
int[] arr = { 8, 5, 0, 10, 0, 20 };

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

moveZerosToLeft(arr);

System.out.println("\nafter moving zeros to front: " + Arrays.toString(arr));
 }

// O(n) time | O(1) space
publicstaticvoidmoveZerosToLeft(int[] arr) {
inttracker = arr.length - 1;
for (inti = arr.length - 1; i >= 0; i--) {
if (arr[i] != 0) {
swap(arr, i, tracker);
tracker--;
 }
 }
 }

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

/*
 * output: original array: [8, 5, 0, 10, 0, 20]
 * 
 * after moving zeros to front: [0, 0, 8, 5, 10, 20]
 */