C program: how to find the maximum/minimum frequency of a character in a string

Question

I am trying to find a way to get the values of max/min freq of characters in a string

E.g. helpme

would have max freq = 2 and min freq = 1 (there are 2 e\'s and

Answer 1

You need to build a histogram:

size_t histogram[UCHAR_MAX] = { 0 };     // allocate and initialise histogram

for (size_t i = 0; s[i] != '\0'; ++i)    // generate histogram for string s
{
    histogram[(unsigned int)s[i]]++;
}

After this you can just do a linear scan through the histogram looking for the min and max letter frequencies.