Php Program to Move all zeroes to end of array
Given an array of random numbers, Push all the zero’s of a given array to the end of the array. For example, if the given arrays is {1, 9, 8, 4, 0, 0, 2, 7, 0, 6, 0}, it should be changed to {1, 9, 8, 4, 2, 7, 6, 0, 0, 0, 0}. The order of all other elements should be same. Expected time complexity is O(n) and extra space is O(1).
Example:
Input : arr[] = {1, 2, 0, 4, 3, 0, 5, 0};
Output : arr[] = {1, 2, 4, 3, 5, 0, 0};
Input : arr[] = {1, 2, 0, 0, 0, 3, 6};
Output : arr[] = {1, 2, 3, 6, 0, 0, 0};
There can be many ways to solve this problem. Following is a simple and interesting way to solve this problem.
Traverse the given array ‘arr’ from left to right. While traversing, maintain count of non-zero elements in array. Let the count be ‘count’. For every non-zero element arr[i], put the element at ‘arr[count]’ and increment ‘count’. After complete traversal, all non-zero elements have already been shifted to front end and ‘count’ is set as index of first 0. Now all we need to do is that run a loop which makes all elements zero from ‘count’ till end of the array.
Below is the implementation of the above approach.
PHP
<?php
function pushZerosToEnd(& $arr , $n )
{
$count = 0;
for ( $i = 0; $i < $n ; $i ++)
if ( $arr [ $i ] != 0)
$arr [ $count ++] = $arr [ $i ];
while ( $count < $n )
$arr [ $count ++] = 0;
}
$arr = array (1, 9, 8, 4, 0, 0,
2, 7, 0, 6, 0, 9);
$n = sizeof( $arr );
pushZerosToEnd( $arr , $n );
echo "Array after pushing all " .
"zeros to end of array :
";
for ( $i = 0; $i < $n ; $i ++)
echo $arr [ $i ] . " " ;
?>
|
Output:
Array after pushing all zeros to end of array :
1 9 8 4 2 7 6 9 0 0 0 0
Time Complexity: O(n) where n is number of elements in input array.
Auxiliary Space: O(1)
Please refer complete article on Move all zeroes to end of array for more details!
Last Updated :
23 Dec, 2021
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