Cant read number char frequency - c

Question

#include <stdio.h>
int main() {
FILE *fb;
char data[255];
int c=0;
int count[75] = {0};
fb = fopen("Input.txt", "r");
fgets(data, 255, fb);
/* Start finding frequency*/
while (data[c] != '\0')
{
if( data[c] >= '0' && data[c] <= 'z')
count[data[c] - 'a']++;
c++;
}
for (c = 0; c < 75; c++)
{
/** Printing only those characters
whose count is at least 1 */
if (count[c] != 0)
printf("%c occurs %d times in the entered string.\n",c+'a',count[c]);
}
return 0;
}
Example input file: "Fred Fish 12345678"
I am able to handle space from the input file, but the program does not read Frequency of capital letter as well as number character. What can I change in the program help fixing the problem. After reading the freq, my plan is to save the file so that I can compress using HUffman

Answer 1

#include <stdio.h>
int main() {
FILE *fb;
char data[255];
int c = 0;
int count[75] = { 0 };
fb = fopen("Input.txt", "r");
fgets(data, 255, fb);
/* Start finding frequency*/
while (data[c] != '\0')
{
if (data[c] >= 'a' && data[c] <= 'z') // here you check normal letters
count[data[c] - 'a']++;
else if (data[c] >= 'A' && data[c] <= 'Z')
count[data[c] - 'A' + 26]++; // Capital letters will be stored after lower cases
else if (data[c] >= '0' && data[c] <= '9')
count[data[c] - '0' + 51]++; // Numbers will be stored after capital letters
c++;
}
// count[] is initialized as following :
// From count[0] to count[25] == Occurence of low case characters
// From count[26] to count[51] == Occurence of capital characters
// From count[52] to count[61] == Occurence of numbers from 0 to 9
for (c = 0; c < 61; c++)
{
/** Printing only those characters
whose count is at least 1 */
if (count[c] != 0) {
if (c < 26)
printf("%c occurs %d times in the entered string.\n", c + 'a', count[c]);
// Starting from 'a', iterating until 'z'
else if (c < 52)
printf("%c occurs %d times in the entered string.\n", c + 'A' - 26, count[c]);
// Same as for low case characters
// Substracting 26 because we already have iterated through the first 26 low case characters
// Starting from 'A' until 'Z'
else if (c >= 52)
printf("%c occurs %d times in the entered string.\n", c + '0' - 51, count[c]);
// Same as for characters
// Substracting 51 because we already have iterated through low cases and capital characters
// Starting from '0' until '9'
}
}
return 0;
}
The problem is that, considering the ascii table, you were storing the capital letters and numbers in a negative indice of your array countby substracting 'a'which is equal to 97in ASCII. This should work but I couldn't test it yet so be careful with it.
For the printing, we do the same thing for low case characters, then capital characters and then numbers : we start from the first one : 'a', then 'A', then '0', iterate until the last one using c and printing them all. We use the fact that in C, 'a' + 1 = 'b', 'A' + 1 = 'B' etc.
For the input Fred Fish 12345678 the output with this code is :
d occurs 1 times in the entered string.
e occurs 1 times in the entered string.
h occurs 1 times in the entered string.
i occurs 1 times in the entered string.
r occurs 1 times in the entered string.
s occurs 1 times in the entered string.
F occurs 2 times in the entered string.
1 occurs 1 times in the entered string.
2 occurs 1 times in the entered string.
3 occurs 1 times in the entered string.
4 occurs 1 times in the entered string.
5 occurs 1 times in the entered string.
6 occurs 1 times in the entered string.
7 occurs 1 times in the entered string.
8 occurs 1 times in the entered string.

Answer 2

I guess chaning the code
count[data[c] - 'a']++;
to
count[data[c] - '0']++;
if data[c] is less than 75, then count[data[c] - 'a'] does not work

Answer 3

You should modify the 'a' to '0' in your code to take all capital letters and numerics into account.
#include <stdio.h>
int main() {
...
/* snippet */
...
while (data[c] != '\0')
{
if( data[c] >= '0' && data[c] <= 'z')
count[data[c] - '0']++;
c++;
}
for (c = 0; c < 75; c++)
{
/** Printing only those characters
whose count is at least 1 */
if (count[c] != 0)
printf("%c occurs %d times in the entered string.\n",c+'0',count[c]);
}
return 0;
}