create map of banned words
for ( int i = 0 ; i < S2 . length ( ) ; ++ i ) { string s = " " ; while ( i < S2 . length ( ) && S2 [ i ] != ' ▁ ' ) s += S2 [ i ++ ] ; banned [ s ] ++ ; } map < string , int > result ; string ans ; int freq = 0 ;