c style (beginner)

[kbat82]

I have this assignment:

Write a program that reads input up to # and reports the number of times that the sequence ei occurs.

I was wondering which method of the two below is preferred (red or green). They both tested fine, but is one better than the other? Would one be faster than the other, or is one more stylistic for programming in c? I prefer the latter, but I don't have any reason why.

I don't have a class and it's not for a grade, I'm just curious. thanks for any input

#include<stdio.h>
#include<stdbool.h>

int main(void) {
    bool e = false;
    int c;
    int count = 0;
    
    printf("Enter something\n");
    
    while ((c = getchar()) != '#') {
        
        /*switch (c) {
            case 'e':
                e = true;
                continue;
            case 'i' :
                if (e) 
                    count++;
            default :                
                e = false;
        }*/
            
        
        if (c == 'e') 
            e = true;
        
        else if (c == 'i') {
            if (e)
                count++;
            e = false;
        }
        else 
            e = false;
    }
    printf("You have %d %s of \"ei\"\n,", count,
        (count == 1) ? "grouping" : "groupings");
    return 0;
}

[tabstop]

I'm not thrilled about the red one -- using continue inside the switch to continue the while loop and using fall through without a comment both are a little bothersome to me.

[MeTh0Dz]

Hmm... Check out this method.

// Some function
#include <stdlib.h>
#include <stdio.h>

int Parse(char * string);

int main(int argc, char * argv[])
{
	if (argc != 2) {
		printf("Correct Format: &#37;s string#\n", argv[0]);
		return 0;
	}
	
	printf("There were %d occurences of 'ei'!\n", Parse(argv[1]));
	return 0;
}

int Parse(char * string)
{
	int amt;
	if (!string) return amt;
	
	for(amt = 0; string[0] != '#' && string[1] != '\0'; string++)
		if (string[0] == 'e' && string[1] == 'i') ++amt;
	return amt;
}

[cas]

Hmm... Check out this method.

// Some function
#include <stdlib.h>
#include <stdio.h>

int Parse(char * string);

int main(int argc, char * argv[])
{
	if (argc != 2) {
		printf("Correct Format: %s string#\n", argv[0]);
		return 0;
	}
	
	printf("There were %d occurences of 'ei'!\n", Parse(argv[1]));
	return 0;
}

int Parse(char * string)
{
	int amt;
	/*if (!string) return amt;*/
	if(string == NULL || string[0] == 0) return 0;
	
	for(amt = 0; string[0] != '#' && string[1] != '\0'; string++)
		if (string[0] == 'e' && string[1] == 'i') ++amt;
	return amt;
}

There are a couple of things I noticed here. First, if string is NULL, an indeterminate value is being returned because amt has not been initialized. Second, if an empty string is passed, the code reads one past the end of the string. The change I made accounts for both of these.

Not a bug, but you'd really want to make the argument to Parse() const since Parse() does not modify the string.

[MeTh0Dz]

Good point, I was careless.

[kbat82]

thanks, but whew...too advanced for me at this point. Hopefully I will understand all that in a couple of months.