C trial n error

#include <stdio.h>
#define NO_OF_CHARS 256
#define N 100

// C function to find the second most frequent character
// in a given string 'str'
char getSecondMostFreq(char *str)
{
    // count number of occurrences of every character.
    int count[NO_OF_CHARS] = {0}, i;
    for (i=0; str[i]; i++)
        (count[str[i]])++;

    // Traverse through the count[] and find second highest element.
    int first = 0, second = 0, third = 0;
    for (i = 0; i < NO_OF_CHARS; i++)
    {
        /* If current element is smaller than first then update both
          first and second */
        if (count[i] > count[first])
        {
        	third = second;
            second = first;
            first = i;
        }

        /* If count[i] is in between first and second then update second  */
        else if (count[i] > count[second] &&
                 count[i] != count[first] &&
				 count[i] != count[third])
            second = i;
    }

    return second;
}

char getThirdMostFreq(char *str)
{
    // count number of occurrences of every character.
    int count[NO_OF_CHARS] = {0}, i;
    for (i=0; str[i]; i++)
        (count[str[i]])++;

    // Traverse through the count[] and find second highest element.
    int first = 0, second = 0, third = 0;
    for (i = 0; i < NO_OF_CHARS; i++)
    {
        /* If current element is smaller than first then update both
          first and second */
        if (count[i] > count[first])
        {
        	third = second;
            second = first;
            first = i;
        }

        /* If count[i] is in between first and second then update second  */
        else if (count[i] != count[second] &&
                 count[i] != count[first] &&
				 count[i] > count[third])
            third = i;
    }

    return third;
}

// Driver program to test above function
int main()
{
  char str[N];
  scanf("%s", &str);
  char res = getSecondMostFreq(str);
  if (res != '\0')
     printf("Second most frequent char is %c", res);
  else
     printf("No second most frequent character");
     char str[] = *str
     char res = getThirdMostFreq(str);
  if (res != '\0')
     printf("Third most frequent char is %c", res);
  else
     printf("No third most frequent character");
  return 0;
}