Frequency of a substring in a string | Simple Java program to count occurrences of pat in txt . ; A loop to slide pat [ ] one by one ; For current index i , check for pattern match ; if pat [ 0. . . M - 1 ] = txt [ i , i + 1 , ... i + M - 1 ] ; Driver program to test above function
class GFG { static int countFreq ( String pat , String txt ) { int M = pat . length ( ) ; int N = txt . length ( ) ; int res = 0 ; for ( int i = 0 ; i <= N - M ; i ++ ) { int j ; for ( j = 0 ; j < M ; j ++ ) { if ( txt . charAt ( i + j ) != pat . charAt ( j ) ) { break ; } } if ( j == M ) { res ++ ; j = 0 ; } } return res ; } static public void main ( String [ ] args ) { String txt = " dhimanman " ; String pat = " man " ; System . out . println ( countFreq ( pat , txt ) ) ; } }