Find Duplicate File

duplicate_files_file_system.java

class Solution {
    public List<List<String>> findDuplicate(String[] paths) {
        Map<String, List<String>> contMap = new HashMap<>();
        StringBuilder pathfile = new StringBuilder();
        for (String pStr : paths) {
            int i = 0;
            pathfile.setLength(0);
            while (pStr.charAt(i) != ' ') i++;
            pathfile.append(pStr.substring(0,i)).append('/');
            int pLen = ++i;
            for (int j = i, k = 0; i < pStr.length(); i++)
                if (pStr.charAt(i) == '(') {
                    pathfile.append(pStr.substring(j,i));
                    k = i + 1;
                } else if (pStr.charAt(i) == ')') {
                    String cont = pStr.substring(k, i);
                    if (!contMap.containsKey(cont))
                        contMap.put(cont, new ArrayList<>());
                    contMap.get(cont).add(pathfile.toString());
                    j = i + 2;
                    pathfile.setLength(pLen);
                }
        }
        List<List<String>> ans = new ArrayList<>();
        for (List<String> v : contMap.values())
            if (v.size() > 1) ans.add(v);
        return ans;
    }
}