811_Subdomain_Visit_Count

qiyuangong · qiyuangong · commit d76e8894d619 · 2018-11-28T22:39:02.000+08:00
diff --git a/README.md b/README.md
@@ -150,6 +150,7 @@ Remember solutions are only solutions to given problems. If you want full study
 | 743 | [Network Delay Time](https://leetcode.com/problems/network-delay-time/) | [Python](https://github.com/qiyuangong/leetcode/blob/master/python/743_Network_Delay_Time.py) [Java](https://github.com/qiyuangong/leetcode/blob/master/java/743_Network_Delay_Time.java) | Let V == N, then: 1. DFS, O(V^V+ElgE), O(V+E)<br>2. Dijkstra, O(V^2+E), O(V+E)|
 | 771 | [Jewels and Stones](https://leetcode.com/problems/jewels-and-stones/description/) | [Python](https://github.com/qiyuangong/leetcode/blob/master/python/771_Jewels_and_Stones.py) [Java](https://github.com/qiyuangong/leetcode/blob/master/java/771_Jewels_and_Stones.java) | Count given char in string. Hash or table. [Oneline](https://leetcode.com/problems/jewels-and-stones/discuss/113574/1-liners-PythonJavaRuby) |
 | 804 | [Unique Morse Code Words](https://leetcode.com/problems/unique-morse-code-words/description/) | [Python](https://github.com/qiyuangong/leetcode/blob/master/python/804_Unique_Morse_Code_Words.py) [Java](https://github.com/qiyuangong/leetcode/blob/master/java/804_Unique_Morse_Code_Words.java) | String, Hash and Set. Set is recommended. |
+| 811 | [Subdomain Visit Count](https://leetcode.com/problems/subdomain-visit-count/) | [Python](https://github.com/qiyuangong/leetcode/blob/master/python/811_Subdomain_Visit_Count.py) [Java](https://github.com/qiyuangong/leetcode/blob/master/java/811_Subdomain_Visit_Count.java) | String split and HashMap, O(n) and O(n) |
 | 819 | [Most Common Word](https://leetcode.com/problems/most-common-word/) | [Python](https://github.com/qiyuangong/leetcode/blob/master/python/819_Most_Common_Word.py) [Java](https://github.com/qiyuangong/leetcode/blob/master/java/819_Most_Common_Word.java) | String processing, be careful about 'b,b,b'. regex is recommended. |
 | 844 | [Backspace String Compare](https://leetcode.com/problems/backspace-string-compare/) | [Python](https://github.com/qiyuangong/leetcode/blob/master/python/844_Backspace_String_Compare.py) [Java](https://github.com/qiyuangong/leetcode/blob/master/java/844_Backspace_String_Compare.java) | 1. Stack pop when encounters #, O(n) and O(n)<br>2. Compare string from end to start, O(n) and O(1) |
 | 904 | [Fruit Into Baskets](https://leetcode.com/problems/fruit-into-baskets/) | [Python](https://github.com/qiyuangong/leetcode/blob/master/python/904_Fruit_Into_Baskets.py) [Java](https://github.com/qiyuangong/leetcode/blob/master/java/904_Fruit_Into_Baskets.java) | 1. Scan through blocks of tree, O(n) and O(n)<br>2. Mainten a sliding window with start and curr point, O(n) and O(n).  |
diff --git a/java/811_Subdomain_Visit_Count.java b/java/811_Subdomain_Visit_Count.java
@@ -0,0 +1,22 @@
+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;
+    }
+}
diff --git a/python/811_Subdomain_Visit_Count.py b/python/811_Subdomain_Visit_Count.py
@@ -0,0 +1,24 @@
+class Solution(object):
+    def subdomainVisits(self, cpdomains):
+        """
+        :type cpdomains: List[str]
+        :rtype: List[str]
+        """
+        domain_count = {}
+        for cpdomain in cpdomains:
+            count, domain = cpdomain.split(' ')
+            sub_domain = domain.split('.')
+            for i in range(len(sub_domain)):
+                curr = '.'.join(sub_domain[i:])
+                domain_count[curr] = domain_count.get(curr, 0) + int(count)
+        return [str(v) + ' ' + k for k, v in domain_count.items()]
+
+
+    # def subdomainVisits(self, cpdomains):
+    #     # https://leetcode.com/problems/subdomain-visit-count/discuss/121770/Python-short-and-understandable-solution-68-ms
+    #     counter = collections.Counter()
+    #     for cpdomain in cpdomains:
+    #         count, *domains = cpdomain.replace(" ",".").split(".")
+    #         for i in range(len(domains)):
+    #             counter[".".join(domains[i:])] += int(count)
+    #     return [" ".join((str(v), k)) for k, v in counter.items()]
