text: Efficient program to print all prime factors of a given number | function to print all prime factors of a given number n ; Print the number of 2 s that divide n ; n must be odd at this point . So we can skip one element ( Note i = i + 2 ) ; While i divides n , print i and divide n ; This condition is to handle the case when n is a prime number greater than 2 ; Driver Code
code: < ? php function primeFactors ( $ n ) { while ( $ n % 2 == 0 ) { echo 2 , " ▁ " ; $ n = $ n / 2 ; } for ( $ i = 3 ; $ i <= sqrt ( $ n ) ; $ i = $ i + 2 ) { while ( $ n % $ i == 0 ) { echo $ i , " " ; $ n = $ n / $ i ; } } if ( $ n > 2 ) echo $ n , " ▁ " ; } $ n = 315 ; primeFactors ( $ n ) ; ? >