add 136

Author: awesomelike

easy/136-single-number.js

@@ -0,0 +1,11 @@
+/**
+ * @param {number[]} nums
+ * @return {number}
+ */
+ var singleNumber = function(nums) {
+  let res = nums[0];
+  for (let i=1; i<nums.length; i++) {
+    res = res ^ nums[i];
+  }
+  return res;
+};