5-bishoe01

bishoe01/README.md

@@ -6,4 +6,5 @@
 | 2차시 | 2025.04.09 |  DP  | [1277. Count Square Submatrices with All Ones](https://leetcode.com/problems/count-square-submatrices-with-all-ones/description/?envType=problem-list-v2&envId=dynamic-programming)|https://github.com/AlgoLeadMe/AlgoLeadMe-14/pull/11|
 | 3차시 | 2025.04.30 |  DP  | [1267. Count Servers that Communicate](https://leetcode.com/problems/count-servers-that-communicate/description/?envType=daily-question&envId=2025-04-29)|https://github.com/AlgoLeadMe/AlgoLeadMe-14/pull/16|
 | 4차시 | 2025.05.09 |  문자열  | [1839. Longest Substring Of All Vowels in Order](https://leetcode.com/problems/longest-substring-of-all-vowels-in-order/description/)|https://github.com/AlgoLeadMe/AlgoLeadMe-14/pull/19|
+| 5차시 | 2025.05.23 |  정렬, 투포인터  | [16. 3Sum Closest](https://leetcode.com/problems/3sum-closest/description/)|https://github.com/AlgoLeadMe/AlgoLeadMe-14/pull/28|
 ---

bishoe01/정렬/3Sum Closest.swift

@@ -0,0 +1,42 @@
+import Foundation
+
+// abs(sum - target)가 가장 작은애 찾기
+
+class Solution {
+    func threeSumClosest(_ nums: [Int], _ target: Int) -> Int {
+        func caculate(_ sum: Int) -> Int {
+            return abs(sum - target)
+        }
+
+//        var answer = 3000 // 최대값 범위 3개 더한 것 으로 해줬는데, target이 높아서 이렇게 해주면 틀리다고 뜸 !
+//        var answer = Int.max // 터짐 - max값에 +가 조금이라도 되니까 펑 터져버리는 이슈가 있음
+        var answer = Int(Int32.max) // 그래서 그나마 값이 조금 작은 큰값으로 해결 
+        var nums = nums
+        nums.sort(by: <)
+        let LEN = nums.count
+        for i in 0 ..< LEN - 2 {
+            var left = i + 1
+            var right = LEN - 1
+            while left < right {
+                let totalSum = nums[i] + nums[left] + nums[right]
+//                print(nums[i], nums[left], nums[right])
+//                print(totalSum)
+//                print(caculate(totalSum))
+                if caculate(totalSum) < caculate(answer) {
+//                    print(nums[i], nums[left], nums[right])
+                    answer = totalSum
+                }
+                if totalSum < target {
+                    left += 1
+                } else if totalSum > target {
+                    right -= 1
+                } else {
+                    return target
+                }
+            }
+        }
+        return answer
+    }
+}
+
+print(Solution().threeSumClosest([1, 1, 1, 1], -100))