2109.Add Spaces To String

class Solution {
    public String addSpaces(String s, int[] spaces) {
        StringBuilder ans=new StringBuilder();
        int i=0;
        int j=0;
        while(i<s.length()){
            while(j<spaces.length && i<s.length() && i!=spaces[j]){
                ans.append(s.charAt(i));
                i++;
            }
             while(j>=spaces.length && i<s.length()){
                 ans.append(s.charAt(i));
                i++;
            }
            if(i!=s.length()){
            ans.append(" ");
            }
            j=j+1;
        }
        return ans.toString();
    }
}