Create 3084-count-substrings-starting-and-ending-with-given-character.js

Author: everthis

3084-count-substrings-starting-and-ending-with-given-character.js

@@ -0,0 +1,22 @@
+/**
+ * @param {string} s
+ * @param {character} c
+ * @return {number}
+ */
+const countSubstrings = function(s, c) {
+  const n = s.length
+  const arr = []
+  for(let i = 0; i < n; i++) {
+    if(s[i] === c) {
+      arr.push(i)
+    }
+  }
+  let len = arr.length
+  let res = 0
+  while(len) {
+    res += len
+    len--
+  }
+  
+  return res
+};