Copying strings between vectors of strings in C - c

Question

I have an array of char pointers (string array), which contains some duplicate values. I've found an algorithm that truncates the array by removing its duplicate values.
Here is a code sample :
int i, j , k;
int n = 10;
char *teams[n];
for(i=0;i<n;i++){
for(j=i+1;j<n;){
if(*(team[j]==*(team[i])){
for(k=j;k<n;k++){
//strcpy(team[k], team[k+1]);
team[k] = team[k+1];
}
n--;
}else{
j++;
}
}
}
I've read that the only way to copy strings between string arrays is to use strcpy(s1, s2). But in my case I can't use it, because strcpy function permits to copy s2 into s1 only if s2 has a lenght equal or bigger than the lenght of s1. So how can I implement this algorithm if I can't put the string pointed by the pointer team[k+1] in team[k] ?

Answer 1

It seems you need to remove duplicated string representations instead of duplicated addresses to strings.
If so then this if statement (if to add missed closed parenthesis)
if( *(team[j] ) ==*( team[i] ) ){
compares only first characters of strings instead of comparing strings pointed to by the pointers.
In this loop
for(k=j;k<n;k++){
//strcpy(team[k], team[k+1]);
team[k] = team[k+1];
}
each time when a duplicates string is found there is copied the whole array of pointers. Moreover there is an attempt to access memory beyond the array in this statement when k is equal to n-1
team[k] = team[k+1];
^^^^
You can write a separate function that will "remove" duplicates. The function can for example return pointer after the last unique element in the modified array.
#include <stdio.h>
#include <string.h>
char ** unique( char *s[], size_t n )
{
size_t i = 0;
for ( size_t j = 0; j < n; j++ )
{
size_t k = 0;
while ( k < i && strcmp( s[k], s[j] ) != 0 ) ++k;
if ( k == i )
{
if ( i != j ) s[i] = s[j];
++i;
}
}
return s + i;
}
int main(void)
{
char * s[] = { "A", "B", "A", "C", "A" };
const size_t N = sizeof( s ) / sizeof( *s );
for ( size_t i = 0; i < N; i++ ) printf( "%s ", s[i] );
printf( "\n" );
char **p = unique( s, N );
size_t n = p - s;
for ( size_t i = 0; i < n; i++ ) printf( "%s ", s[i] );
printf( "\n" );
return 0;
}
The program output is
A B A C A
A B C

Answer 2

#include <stdio.h>
#include <string.h>
unsigned dedup(char **arr, unsigned count)
{
unsigned this, that ;
for(this=0;this<count;this++){
for(that=this+1;that<count;){
if( strcmp(arr[that], arr[this])) {that++; continue; }
#if PRESERVE_ORDER
memmove(arr+that, arr+that+1, (--count - that) * sizeof arr[that] );
#else
arr[that] = arr[--count];
#endif
}
}
return count; /* the count after deduplication */
}
char *array[] = { "one", "two", "three", "two", "one", "four", "five", "two" };
int main(void)
{
unsigned count, index;
count = dedup(array, 8);
for (index = 0; index < count; index++) {
printf("%s\n", array[index] );
}
return 0;
}
[UPDATED]: I added the PRESERVE_ORDER version