Position of n among the numbers made of 2 , 3 , 5 & 7 | PHP Program position of n among the numbers made of 2 , 3 , 5 & 7 ; If number is 2 then it is on the position pos * 2 + 1 ; If number is 3 then it is on the position pos * 2 + 2 ; If number is 5 then it is on the position pos * 2 + 3 ; If number is 7 then it is on the position pos * 2 + 4 ; Driver Code
< ? php function findpos ( $ n ) { $ pos = 0 ; for ( $ i = 0 ; isset ( $ n [ $ i ] ) != NULL ; $ i ++ ) { switch ( $ n [ $ i ] ) { case '2' : $ pos = $ pos * 4 + 1 ; break ; case '3' : $ pos = $ pos * 4 + 2 ; break ; case '5' : $ pos = $ pos * 4 + 3 ; break ; case '7' : $ pos = $ pos * 4 + 4 ; break ; } } return $ pos ; } $ n = "777" ; echo findpos ( $ n ) ; ? >