question: private String substituteSubString ( String input , String find , String replace ) { int find_length = find . length ( ) ; int replace_length = replace . length ( ) ; StringBuilder output = new StringBuilder ( input ) ; int index = input . indexOf ( find ) ; int outputOffset = 0 ; while ( index > - 1 ) { output . replace ( index + outputOffset , index + outputOffset + find_length , replace ) ; outputOffset = outputOffset + ( replace_length - find_length ) ; index = input . indexOf ( find , index + find_length ) ; } return output . toString ( ) ; }
target:  Replace substrings of one string with another string and return altered string.