diff --git a/3sum/higeuni.js b/3sum/higeuni.js
index 07a265f3d..d08950171 100644
--- a/3sum/higeuni.js
+++ b/3sum/higeuni.js
@@ -1,6 +1,11 @@
 // complexity
 // time: O(n^2)
+// - sort: O(n log n)
+// - for loop: O(n)
+// - while loop: O(n)
 // space: O(n)
+// - sortedNums: O(n)
+// - else : O(1)
 
 var threeSum = function(nums) {
   const sortedNums = nums.sort((a, b) => a - b)
diff --git a/climbing-stairs/higeuni.js b/climbing-stairs/higeuni.js
index 9bce31079..ea9b321e0 100644
--- a/climbing-stairs/higeuni.js
+++ b/climbing-stairs/higeuni.js
@@ -1,6 +1,8 @@
 // complexity
 // time: O(n)
+// - for loop: O(n)
 // space: O(1)
+// - n에 관계없이 상수개의 변수만 사용되므로 O(1)
 
 var climbStairs = function(n) {
   let num1 = 1;
diff --git a/valid-anagram/higeuni.js b/valid-anagram/higeuni.js
index a1aef97f5..72e662abc 100644
--- a/valid-anagram/higeuni.js
+++ b/valid-anagram/higeuni.js
@@ -1,6 +1,12 @@
 // complexity
 // time: O(n log n)
+// - sort: O(n log n)
+// - split: O(n)
+// - join: O(n)
 // space: O(n)
+// - sortedS: O(n)
+// - sortedT: O(n)
+// - else : O(1)
 
 var isAnagram = function(s, t) {
   return s.split('').sort().join('') === t.split('').sort().join('')