#medium

#N791. Custom Sort String
problem link

#solution

class Solution {
    public String customSortString(String order, String s) {
        StringBuilder res=new StringBuilder();
        char[] arr1=order.toCharArray();
        char[] arr2=s.toCharArray();
        
        for(int i=0; i<order.length(); i++){
            for(int j=0; j<s.length(); j++){
                if(arr1[i]==arr2[j]){
                    res.append(""+arr1[i]);
                    arr2[j]=' ';
                }
            }
        }
        
        for(int i=0; i<arr2.length; i++){
            if(arr2[i]!=' ')
                res.append(""+arr2[i]);
        }
        
        return res.toString();
    }
}

p.s. runtime is O(m•n). the worst ever