Add solutions : 3sum and add blank line

Author: HiGeuni

3sum/higeuni.js

@@ -0,0 +1,36 @@
+// complexity
+// time: O(n^2)
+// space: O(n)
+
+var threeSum = function(nums) {
+  const sortedNums = nums.sort((a, b) => a - b)
+  const lengthOfArray = nums.length;
+  const answer = [];
+
+  for(let i = 0; i < lengthOfArray; i++ ) {
+      if (i > 0 && nums[i] === nums[i - 1]) continue;
+      const target = (-1) * sortedNums[i];
+
+      let left = i + 1;
+      let right = lengthOfArray - 1;
+
+      while(left < right) {
+          const sumOfLeftAndRight = sortedNums[left] + sortedNums[right];
+          const diff = sumOfLeftAndRight - target;
+
+          if( diff > 0 ){
+              right -= 1;
+          } else if ( diff < 0 ){
+              left += 1
+          } else {
+              answer.push([sortedNums[i], sortedNums[left], sortedNums[right]]);
+              while(left < right && sortedNums[left] === sortedNums[left + 1]) left ++;
+              while(left < right && sortedNums[right] === sortedNums[right - 1]) right --;
+              
+              left++;
+              right--;
+          }
+      }
+  }
+  return answer
+};

climbing-stairs/higeuni.js

@@ -14,4 +14,4 @@ var climbStairs = function(n) {
   }
 
   return num2;
-};
+};

valid-anagram/higeuni.js

@@ -4,4 +4,4 @@
 
 var isAnagram = function(s, t) {
   return s.split('').sort().join('') === t.split('').sort().join('')
-};
+};