Humming Distance and Repeated Substring Pattern

puzzles/interviews/training/repeated_substring_pattern.cpp

@@ -0,0 +1,41 @@
+/*
+LeetCode
+459. Repeated Substring Pattern
+Easy
+
+Given a non-empty string check if it can be constructed by taking a substring of it and appending multiple copies of the substring together. You may assume the given string consists of lowercase English letters only and its length will not exceed 10000.
+
+
+
+Example 1:
+
+Input: "abab"
+Output: True
+Explanation: It's the substring "ab" twice.
+
+Example 2:
+
+Input: "aba"
+Output: False
+
+Example 3:
+
+Input: "abcabcabcabc"
+Output: True
+Explanation: It's the substring "abc" four times. (And the substring "abcabc" twice.)
+
+
+*/
+bool repeatedSubstringPattern(string s) {
+    size_t n = (s.size()+1)/2;
+    for (size_t i = 1; i <= n; ++i){
+        if (s[i] == s[0] && s.size() % i == 0){
+            size_t j = i;
+            for (; j < s.size() && s[j] == s[j-i]; ++j);
+            if (j == s.size()){
+                return true;
+            }
+        }
+    }
+    return false;
+}