Thread: what would I use to count number of words

quick question, I have a string

Code:

int main ( )
{
char string [ 25 ] = "Hello My  Name  is   Ben";

}

How would I count the number of words in the string? I tried counting the number of spaces but if they put more than one space between each word It would throw me off.

Thanks in advance.

how in the heck would you ignore spaces after a space?

Isnt there a way to break up a string into tokens?

and you use strtok how?

Think of the problem in terms of state machines. For simplicity I'll describe a Moore type state machine that would do the trick. (A Mealy type would be more efficient and I recommend you convert this to Mealy.) In each state there will be an action that is performed (e.g. increment the word count) and a set of conditions that dictate transitions to new states.

Here are some proposed states:

StartWord: (Occurs when we first detect a word)
Action: increment word counter
whitespace: go to White state
ascii: if not white go to Word state

White: (Occurs when we are processing white characters (e.g. space, tab newline etc.))
Action: none
whitespace: go to White state
ascii: go to StartWord

Word: You can figure this out yourself.


C implementation. The standard and inefficent approach will be to implement this using the switch statement. The state values would be determined via #define statements

switch(state) {
case StartWord:
wordcount++ ;
if ((c == ' ') || (c == '/t') || (c == '\n')) {
state = White ;
} else {
state = Word ;
}
break
case White:
....
break ;
case Word:
...
break ;
}

The superior approach is to use the dreaded goto statement to handle the state transitions. c would contain the current character and the whole mess would be wrapped in a while loop, whilst reading one character at a time from the input stream (e.g. using getchar() or scanf etc.). Although goto is strongly discouraged in structured programming, it makes perfect sense for a state machine and really is not any harder to read than a switch statement for this purpose. It's when go tos jump out of loops that things get messy.

Although goto is strongly discouraged in structured programming, it makes perfect sense for a state machine and really is not any harder to read than a switch statement for this purpose.

I don't believe that. Can you prove it?

Originally Posted by SevenThunders

The superior approach is to use the dreaded goto statement to handle the state transitions. c would contain the current character and the whole mess would be wrapped in a while loop, whilst reading one character at a time from the input stream (e.g. using getchar() or scanf etc.). Although goto is strongly discouraged in structured programming, it makes perfect sense for a state machine and really is not any harder to read than a switch statement for this purpose. It's when go tos jump out of loops that things get messy.

You don't need goto...

Code:

#include <ctype.h>

#define IN_WORD 0
#define IN_SPACE 1

int count_words(const char *str)
{
    int nwords = 0;
    int state;

    if(!*str) return 0;
    if(isspace(*str)) state = IN_SPACE;
    else
    {
        state = IN_WORD;
        nwords = 1;
    }
    while(*++str)
    {
        switch(state)
        {
        case IN_SPACE:
            if(!isspace(*str))
            {
                state = IN_WORD;
                nwords++;
            }
            break;
        case IN_WORD:
            if(isspace(*str)) state = IN_SPACE;
            break;
        }
    }
    return nwords;
}

Originally Posted by MacGyver

How would you do it yourself?

Count spaces, but ignore all spaces preceeded by a space.

Wouldn't work. Take the simple rule of counting the spaces and then adding one. There is one space in "Two Words," 1+1 = 2, so there are 2 words. It's simple to add the rule "except when a space is preceded by another space." But if the input string is two spaces and nothing else, there is one space which is not preceded by a space, so there is 1 counted space. Add 1 to this according to the aforementioned rule, and you get the result that a string consisting only of 2 or more spaces contains 2 words.

My program should at the moment read from a file called input, create two new files called east and west. And then print Roster number x for each player. Right now I am working on how to break up each word in the input file into tokens. and print them off in this order.

Roster# Lastname, Firstname, Hometeam, Scoring average

my input file is

Code:

Joseph Stevens Boys 11 20 5
Jamie Stevens Girls 22 18 6
Tony Waters Boys 33 22 7
Sally Smith Girls 44 33 8

My program is:

Code:

int main ( void )
{
char str [ 80 ];
char first;
char last;
char *token;
int points;
int games;
int number;
int x;
int roster;
int y;
int a = 0;
FILE * input, * east, * west;
char array [ 81 ];
char string [ 80 ] = "Hello My Name is Ben";

if ( ( input = fopen ( "input", "r" ) ) == NULL )
{
        printf ( "Cannot open file\n" );
        exit ( 1 );
}

if ( ( east = fopen ( "east", "w" ) ) == NULL )
{
        printf ( "Cannot open file\n" );
        exit ( 1 );
}

if ( ( west = fopen ( "west", "w" ) ) == NULL )
{
        printf ( "Cannot open file\n" );
        exit ( 1 );
}

"mylab8.c" 73 lines, 1259 characters
}

x = -1;
while ( ! feof ( input ) )
        {
        fgets (str, 80, input );
        x ++;
        }
y = x + 1;
for (roster = 1; roster < y; roster ++)
        {
        fprintf (east, "Roster# is %d\n", roster);
        fprintf (west, "Roster# is %d\n", roster);
        }
fgets (str, 80, input );

stringtoken ( str );

}


int stringtoken ( char string )

{
char *token;

   printf( "Tokens:\n" );
   /* Establish string and get the first token: */
   token = strtok( string, " ,\n\t" );
   while( token != NULL )
   {
      /* While there are tokens in "string" */
      printf( " %s\n", token );
      /* Get next token: */
      token = strtok( NULL, " ,\n\t" );
   }
}

And my error when I try to compile is

mylab8.c:60: warning: type mismatch with previous implicit declaration
mylab8.c:53: warning: previous implicit declaration of `stringtoken'
mylab8.c: In function `stringtoken':
mylab8.c:65: warning: assignment makes pointer from integer without a cast
mylab8.c:71: warning: assignment makes pointer from integer without a cast

Originally Posted by s_jsstevens

My program should at the moment read from a file called input, create two new files called east and west. And then print Roster number x for each player. Right now I am working on how to break up each word in the input file into tokens. and print them off in this order.

Why are you posting this here?