Add solution #1316

Author: JoshCrozier

README.md

@@ -1,4 +1,4 @@
-# 1,228 LeetCode solutions in JavaScript
+# 1,229 LeetCode solutions in JavaScript
 
 [https://leetcodejavascript.com](https://leetcodejavascript.com)
 
@@ -997,6 +997,7 @@
 1313|[Decompress Run-Length Encoded List](./solutions/1313-decompress-run-length-encoded-list.js)|Easy|
 1314|[Matrix Block Sum](./solutions/1314-matrix-block-sum.js)|Medium|
 1315|[Sum of Nodes with Even-Valued Grandparent](./solutions/1315-sum-of-nodes-with-even-valued-grandparent.js)|Medium|
+1316|[Distinct Echo Substrings](./solutions/1316-distinct-echo-substrings.js)|Hard|
 1317|[Convert Integer to the Sum of Two No-Zero Integers](./solutions/1317-convert-integer-to-the-sum-of-two-no-zero-integers.js)|Easy|
 1318|[Minimum Flips to Make a OR b Equal to c](./solutions/1318-minimum-flips-to-make-a-or-b-equal-to-c.js)|Medium|
 1319|[Number of Operations to Make Network Connected](./solutions/1319-number-of-operations-to-make-network-connected.js)|Medium|

solutions/1316-distinct-echo-substrings.js

@@ -0,0 +1,36 @@
+/**
+ * 1316. Distinct Echo Substrings
+ * https://leetcode.com/problems/distinct-echo-substrings/
+ * Difficulty: Hard
+ *
+ * Return the number of distinct non-empty substrings of text that can be written as the
+ * concatenation of some string with itself (i.e. it can be written as a + a where a is
+ * some string).
+ */
+
+/**
+ * @param {string} text
+ * @return {number}
+ */
+var distinctEchoSubstrings = function(text) {
+  const set = new Set();
+
+  for (let size = 1; size <= text.length / 2; size++) {
+    let count = 0;
+
+    for (let left = 0, right = size; right < text.length; left++, right++) {
+      if (text[left] === text[right]) {
+        count++;
+      } else {
+        count = 0;
+      }
+
+      if (count === size) {
+        set.add(text.slice(left - size + 1, right + 1));
+        count--;
+      }
+    }
+  }
+
+  return set.size;
+};