add 647-Palindromic-Substrings

loczek · web-flow · commit d093d65121a4 · 2022-07-06T18:54:15.000+02:00
diff --git a/javascript/647-Palindromic-Substrings.js b/javascript/647-Palindromic-Substrings.js
@@ -0,0 +1,25 @@
+function countSubstrings(s) {
+  let res = 0;
+
+  for (let i = 0; i < s.length; i++) {
+    let l = i;
+    let r = i;
+
+    while (l >= 0 && r < s.length && s[l] === s[r]) {
+      res += 1;
+      l -= 1;
+      r += 1;
+    }
+
+    l = i;
+    r = i + 1;
+
+    while (l >= 0 && r < s.length && s[l] === s[r]) {
+      res += 1;
+      l -= 1;
+      r += 1;
+    }
+  }
+
+  return res;
+}
