Repeated Substring Pattern

src/s0459_repeated_substring_pattern.cpp

@@ -0,0 +1,32 @@
+#include "s0459_repeated_substring_pattern.hpp"
+
+void S0459::getNext(string &s, int *next) {
+  int j{0};
+  int len = s.size();
+  next[0] = 0;
+  for (int i{1}; i < len; ++i) {
+    while (j > 0 && s[i] != s[j]) {
+      j = next[j - 1];
+    }
+    if (s[i] == s[j]) {
+      ++j;
+    }
+    next[i] = j;
+  }
+}
+
+bool S0459::repeatedSubstringPattern(string s) {
+  int len = s.size();
+  if (len <= 1) {
+    return false;
+  }
+  int next[len];
+  getNext(s, next);
+  if (next[len - 1] == 0) {
+    return false;
+  } else if (len % (len - next[len - 1]) == 0) {
+    return true;
+  } else {
+    return false;
+  }
+}