Add Q187

Author: theFool32

187_RepeatedDNASequences/RepeatedDNASequences.cc

@@ -0,0 +1,17 @@
+class Solution {
+public:
+    vector<string> findRepeatedDnaSequences(string s) {
+        vector<string> ans;
+        unordered_map<string, int> m;
+        for (int i = 0; i+9 < s.size(); ++i) {
+            string sub = s.substr(i, 10);
+            ++m[sub];
+        }
+        for (auto&& p : m) {
+            if (p.second > 1) {
+                ans.push_back(p.first);
+            }
+        }
+        return ans;
+    }
+};