class Solution {

public List<String> subdomainVisits(String[] cpdomains) {

// https://leetcode.com/problems/subdomain-visit-count/discuss/121738/C%2B%2BJavaPython-Easy-Understood-Solution

Map<String, Integer> map = new HashMap();

for (String cpdomain : cpdomains) {

int i = cpdomain.indexOf(' ');

int n = Integer.valueOf(cpdomain.substring(0, i));

String domain = cpdomain.substring(i + 1);

for (i = 0; i < domain.length(); ++i) {

if (domain.charAt(i) == '.') {

String d = domain.substring(i + 1);

map.put(d, map.getOrDefault(d, 0) + n);

}

}

map.put(domain, map.getOrDefault(domain, 0) + n);

}

List<String> res = new ArrayList();

for (String domain : map.keySet()) res.add(map.get(domain) + " " + domain);

return res;

}

}