Question

Just your standard C primer program. I’m trying to print out a histogram of all the different characters that a user inputs as a string.

#include <stdio.h>


#define LIMIT 255


main(){
int asciiArray[LIMIT], input, outer, inner;

while((input = getchar()) != EOF){
    asciiArray[input] = ++asciiArray[input];
    //printf("%d\n", asciiArray[input]);
}
for(outer = 0; outer <= LIMIT; outer++){
    if(asciiArray[outer] < 0){
        putchar(outer);
        printf("\t");
        for(inner = asciiArray[outer]; inner > 1; inner--)
            printf("*");
        printf("\n");       
    }
    else
        ;
}

}

These are the results when the user inputs “h”:

h0
2
9
?
@
C
G
J
K
U
Z
a
b
h
j
l
n
q
}
�
�
�
�
�
�
�
�
�
�
�
�
�
�
�
�
�
�
�
�
�
�
�
�
�
�
�
�

Answer 1

For starters, you are not initializing asciiArray, thus it may contain everything.

Try memset(asciiArray, 0, sizeof(asciiArray)); or int asciiArray[LIMIT] = {0}.

Also, you can simplify that increment in the while to: asciiArray[input]++.

The for looks fishy too (especially how it accesses asciiArray[255]). What’s more, I don’t see how asciiArray[outer] can be less than 0 Perhaps you meant > ?.