need help with deja vu challenge in C

Question

Output is only Unique. is my logic wrong?
Heres my code:
#include <stdio.h>
#include <string.h>
int main() {
char str[100];
fgets(str,sizeof str,stdin);
int i;
int j;
char l;
char k;
int len = strlen(str);
for(i = 0;i < len;i++){
l = str[i];
for(j = i+1;j < len;j++){
k = str[j];
if(l != k){
printf("Deja Vu");
exit(1);
}
else{
printf("Unique");
exit(1);
}
}
}
return 0;
}

Answer 1

Try this:
#include <stdio.h>
#include <string.h>
int main()
{
int flag = 1;
char str[100];
fgets(str,sizeof(str),stdin);
for(int i=0;i<strlen(str);i++)
{
for(int j=i+1;j<strlen(str);j++)
{
if(str[i] == str[j])
{
flag = 0;
break;
}
}
}
if(flag)
{
printf("Unique");
}
else
{
printf("Deja Vu");
}
return 0;
}

Answer 2

You only checked str[0] which is str[i] and str[1] which is str[j]. When str[0] != str[1] it prints "deja vu", else prints "Unqiue".

Answer 3

CarrieForle i don’t get it...