Longest subsequence where each character occurs at least k times | Function to find the subsequence ; Taking an extra array to keep record for character count in s ; Counting occurrences of all characters in str [ ] ; Printing characters with count >= k in same order as they appear in str . ; Driver code
< ? php function findSubsequence ( $ str , $ k ) { $ a = array ( 1024 ) ; for ( $ i = 0 ; $ i < 26 ; $ i ++ ) $ a [ $ i ] = 0 ; for ( $ i = 0 ; $ i < strlen ( $ str ) ; $ i ++ ) { $ temp = ord ( $ str [ $ i ] ) - ord ( ' a ' ) ; $ a [ $ temp ] += 1 ; } for ( $ i = 0 ; $ i < strlen ( $ str ) ; $ i ++ ) if ( $ a [ ord ( $ str [ $ i ] ) - ord ( ' a ' ) ] >= $ k ) echo $ str [ $ i ] ; } $ k = 2 ; findSubsequence ( " geeksforgeeks " , $ k ) ; ? >