Question

Write the C-code for a function which returns the least common character in an set of characters that occurs at least once. (The function's prototype is char least_common(int, unsigned char*);)

Answer 1

#include<conio.h>
#include<stdio.h>

unsigned char least_common(unsigned char *s, int size){
   int i;
   int freq[26] = {0};
   int min = size, minIndex = -1;
   char ch;
   for (i=0;i<size;i++){
       ch = s[i];
       if(ch >= 'a' && ch<='z'){
             freq[ch-'a']++;
       }
       else if( ch >= 'A' && ch<='Z'){
             freq[ch-'A']++;
       }
   }
   for(i = 0;i<26;i++){
       if(min> freq[i] && freq[i] > 0){
           minIndex = i;
           min = freq[i];
       }
   }
   return 'a'+minIndex;
}

int main(int argc, char *argv[]) {
   printf("Most frequent = %c\n",least_common("testString",10));
   getch();
   return 0;
}

Most frequent e Process exited after 5.237 seconds with returnvalue 0 Press any key to continue - - -

$\color{red}Please\; upvote\;the \;solution \;if \;it \;helped.\;Thanks!$