Minimum Deletions to Make String Balanced.java

// Runtime: 38 ms (Top 70.64%) | Memory: 68.2 MB (Top 24.02%)
class Solution {
    public int minimumDeletions(String s) {
        //ideal case : bbbbbbbbb
        int[] dp = new int[s.length()+1];
        int idx =1;
        int bCount=0;

        for(int i =0 ;i<s.length();i++)
        {
            if(s.charAt(i)=='a')
            {
             dp[idx] = Math.min(dp[idx-1]+1,bCount);
            }
            else
            {
                dp[idx]=dp[idx-1];
                bCount++;
            }

            idx++;
        }
        return dp[s.length()];

    }
}