Check a given sentence for a given set of simple grammer rules | C program to validate a given sentence for a set of rules ; Method to check a given sentence for given rules ; Calculate the length of the string . ; Check that the first character lies in [ A - Z ] . Otherwise return false . ; If the last character is not a full stop ( . ) no need to check further . ; Maintain 2 states . Previous and current state based on which vertex state you are . Initialise both with 0 = start state . ; Keep the index to the next character in the string . ; Loop to go over the string . ; Set states according to the input characters in the string and the rule defined in the description . If current character is [ A - Z ] . Set current state as 0. ; If current character is a space . Set current state as 1. ; If current character is [ a - z ] . Set current state as 2. ; If current state is a dot ( . ) . Set current state as 3. ; Validates all current state with previous state for the rules in the description of the problem . ; If we have reached last state and previous state is not 1 , then check next character . If next character is ' \0' , then return true , else false ; Set previous state as current state before going over to the next character . ; Driver program
#include <stdio.h> NEW_LINE #include <string.h> NEW_LINE #include <stdbool.h> NEW_LINE bool checkSentence ( char str [ ] ) { int len = strlen ( str ) ; if ( str [ 0 ] < ' A ' str [ 0 ] > ' Z ' ) return false ; if ( str [ len - 1 ] != ' . ' ) return false ; int prev_state = 0 , curr_state = 0 ; int index = 1 ; while ( str [ index ] ) { if ( str [ index ] >= ' A ' && str [ index ] <= ' Z ' ) curr_state = 0 ; else if ( str [ index ] == ' ▁ ' ) curr_state = 1 ; else if ( str [ index ] >= ' a ' && str [ index ] <= ' z ' ) curr_state = 2 ; else if ( str [ index ] == ' . ' ) curr_state = 3 ; if ( prev_state == curr_state && curr_state != 2 ) return false ; if ( prev_state == 2 && curr_state == 0 ) return false ; if ( curr_state == 3 && prev_state != 1 ) return ( str [ index + 1 ] == ' \0' ) ; index ++ ; prev_state = curr_state ; } return false ; } int main ( ) { char * str [ ] = { " I ▁ love ▁ cinema . " , " The ▁ vertex ▁ is ▁ S . " , " I ▁ am ▁ single . " , " My ▁ name ▁ is ▁ KG . " , " I ▁ lovE ▁ cinema . " , " GeeksQuiz . ▁ is ▁ a ▁ quiz ▁ site . " , " I ▁ love ▁ Geeksquiz ▁ and ▁ Geeksforgeeks . " , " ▁ You ▁ are ▁ my ▁ friend . " , " I ▁ love ▁ cinema " } ; int str_size = sizeof ( str ) / sizeof ( str [ 0 ] ) ; int i = 0 ; for ( i = 0 ; i < str_size ; i ++ ) checkSentence ( str [ i ] ) ? printf ( " \" % s \" ▁ is ▁ correct ▁ STRNEWLINE " , str [ i ] ) : printf ( " \" % s \" ▁ is ▁ incorrect ▁ STRNEWLINE " , str [ i ] ) ; return 0 ; }