def alternatingCharacters(s):
    # Write your code here
    i=0
    count = 0
    s = list(s)
    while i < len(s) - 1:
        if s[i] == s[i+1]: 
            count+=1
            s.remove(s[i+1])
            continue
        i+=1
    return count

public static int alternatingCharacters(String s) {
    int deletions = 0;

    for (int i = 0; i < s.length() - 1; i++) {
        if (s.charAt(i) == s.charAt(i + 1)) {
            deletions++;
        }
    }

    return deletions;
}

int alternatingCharacters(char* s) {
    int i=0,j,count=0;
    while(s[i]!='\0'){
    char ch = s[i];
    j=i+1;
    while(s[j]==s[i] && s[j]!='\0'){
        j++;
        i++;
        count++;
    }
    if(s[j]=='\0')
        break;
    i++;
  }
  return count;
}

def alternatingCharacters(s:str):
    
    count = 0
    for i in range(len(s)-1):
        if s[i] == s[i+1]:
            count +=1
    return count

def alternatingCharacters(s):
    ch = s[0]
    remove = 0
    
    for i in range(1, len(s)):
        if s[i] == ch:
            remove += 1
        
        if s[i] != ch:
            ch = s[i]
    
    return remove