add solution 038[js]

Author: limbowandering

solution/038.Count and Say/Solution.js

@@ -0,0 +1,18 @@
+const countAndSay = function(n){
+  let s = '1';
+
+  for(let i = 2; i <= n; i++){
+    let count = 1, str = '', len = s.length;
+
+    for(let j = 0 ; j < len; j++){
+      if(j < len - 1 && s[j] === s[j + 1]){
+        count++;
+      }else{
+        str += `${count}${s[j]}`;
+        count = 1;
+      }
+    }
+    s = str;
+  }
+  return s;
+}