Question

Find the minimum number of operations to make all the characters in a string equal.

Given:
You are given a string S of length N consisting of lowercase characters 'a' and 'b'. In one operation, you can select a character and make it equal to one of its adjacent characters. For example, if S = Aab", in one operation you can convert it to any of the following:
1. Aab": By changing the 1st character to the 2nd character.
2. Aab": By changing the 2nd character to the 1st character.
3. Abb": By changing the 2nd character to the 3rd character.
4. Aaa": By changing the 3rd character to the 2nd character.

Answer 1

The minimum number of operations to make all the characters in a string equal is determined by turning all characters into the one that appears most frequently and is equal to the count of the less frequent character.

Step-by-step explanation:

The question is asking for the minimum number of operations required to convert a given string of lowercase characters 'a' and 'b' into a string with all identical characters. The most efficient method to achieve this is to turn the characters into the one that appears most frequently in the string, thereby minimizing the number of changes required.

To determine the minimum number of operations, we first count the number of 'a' and 'b' characters in the string. If the count of 'a' is greater than or equal to the count of 'b', we change all 'b' characters to 'a'. Else, we change all 'a' characters to 'b'. The number of operations needed will be equal to the count of the character that is less frequent in the string.

For example, if S = "abba", we have two 'a' characters and two 'b' characters. We can change all characters to either 'a' or 'b' in two operations. Therefore, the minimum number of operations is 2 in this case.

Following these steps will always provide us with the optimal solution to make all characters in the string equal.