How to remove all repeated character in character array - arrays

Question

I want to remove all the repeated characters from array. here is example.
"aabccdee"
"bd"
I'm doing this C language. use only array, loop, if,else(conditional statements) not using pointer.
#include<stdio.h>
int main() {
char c[10];
char com[10] = {0,};
char result[10] = { 0, };
int cnt = 0;
for (int i = 0; i < 10; i++) {
scanf("%c", &c[i]);
}
for (int i = 0; i < 10; i++) {
for (int j = i+1; j < 10; j++) {
if (c[i] == c[j]) {
com[i] = c[i];
cnt++;
printf("%c", com[i]);
}
}
}
for (int i = 0; i < cnt; i++) {
for (int j = 0; j < 10; j++) {
if (com[i] != c[j]) {
result[j] = c[j];
}
}
}
printf("\n");
for (int i = 0; i < 10; i++) {
printf("%c", result[i]);
}
}
I thought this
Make repeated array
Compare original array to repeated array
Output
But repeated array loop can't looping all original array.
How can I do remove all repeated character?

Answer 1

Not good SO policy to blatantly answer homework, but I rarely do it and thought this was an interesting task. Certainly making no claims on efficiency, but it looks like it works to me. As far as I can tell, the first and last cases are corner cases, so I handle those individually, and use a loop for everything in the middle. If you're not allowed to use strlen, then you can roll your own or use some other method, that's not the primary focus of this problem (would be best to fgets the string from a command line argument).
#include <stdio.h>
#include <string.h>
int main(void)
{
char source[] = "aabccdee";
char result[sizeof(source)] = { 0 };
unsigned resultIndex = 0;
unsigned i = 0;
// do this to avoid accessing out of bounds of source.
if (strlen(source) > 1)
{
// handle the first case, compare index 0 to index 1. If they're unequal, save
// index 0.
if (source[i] != source[i+1])
{
result[resultIndex++] = source[i];
}
// source[0] has already been checked, increment i to 1.
i++;
// comparing to strlen(source) - 1 because in this loop we are comparing the
// previous and next characters to the current. Looping from 1 to second-to-the-
// last char means we stay in bounds of source
for ( ; i < strlen(source) - 1; i++)
{
if (source[i-1] != source[i] && source[i] != source[i+1])
{
// write to result if curr char != prev char AND curr char != next char
result[resultIndex++] = source[i];
}
}
// handle the end. At this point, i == the last index of the string. Compare to
// previous character. If they're not equal, save the last character.
//
if (source[i] != source[i-1])
{
result[resultIndex] = source[i];
}
}
else if (strlen(source) == 1)
{
// if source is only 1 character, then it's trivial
result[resultIndex] = source[i];
}
else
{
// source has no length
fprintf(stderr, "source has no length.\n");
return -1;
}
// print source and result
printf("source = %s\n", source);
printf("result = %s\n", result);
return 0;
}
Various outputs for source:
source = "aabccdee"
result = "bd"
source = "aaee"
result =
source = "a"
result = "a"
source = "abcde"
result = "abcde"
source = "abcdee"
result = "abcd"
source = "aabcde"
result = "bcde"
source = "aaaaaaaaaaaabdeeeeeeee"
result = "bd"
source = ""
source has no length.

Answer 2

first of all before we speak , you have to check this
you need to put a whitespace when scaning a char using scanf
so
scanf("%c", &c[i]);
becomes
scanf(" %c", &c[i]);
secondly your idea is kinda a messy as the result showed you're only handling cases and it doesn't continue verifying the whole array . you need to learn how to shift an array to the right or left
your issue later on that when you shift your table(not completely) you still print out of the size .
so bascilly in general your code should be something like this :
#include<stdio.h>
int main() {
char c[10];
int length=5;
for (int i = 0; i < 5; i++) {
scanf(" %c", &c[i]);
}
int j,k,i;
for(i=0; i<length; i++)
{
for(j=i+1; j<length; j++)
{
if(c[i] == c[j])
{
length--;
for(k=j; k<length; k++)
{
c[k] = c[k + 1];
}
j--;
}
}
}
printf("\n");
for (int i = 0; i < length; i++) {
printf("%c", c[i]);
}
}
you simply take one case and compare it to the rest , if it exists you shift from the position you find for the second time the element and so on