From df78dc2f2e51f966232183e7f14d15f3204bfe81 Mon Sep 17 00:00:00 2001 From: juhui Date: Mon, 2 Mar 2026 12:02:32 +0900 Subject: [PATCH 1/4] WEEK 1 Solutions --- contains-duplicate/juhui-jeong.java | 38 +++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+) create mode 100644 contains-duplicate/juhui-jeong.java diff --git a/contains-duplicate/juhui-jeong.java b/contains-duplicate/juhui-jeong.java new file mode 100644 index 0000000000..dde6b6c4e0 --- /dev/null +++ b/contains-duplicate/juhui-jeong.java @@ -0,0 +1,38 @@ +/* + +// 첫번째 풀이 +class Solution { + public boolean containsDuplicate(int[] nums) { + for (int i=0; i < nums.length; i++) { + for (int j=i+1; j < nums.length; j++) { + if (nums[i] == nums[j]) return true; + } + } + return false; + } +} + +// 두번째 풀이 +class Solution { + public boolean containsDuplicate(int[] nums) { + Set set = new HashSet(); + for (int i=0; i < nums.length; i++) { + set.add(nums[i]); + } + + if (set.size() != nums.length) return true; + return false; + } +} + +*/ + +class Solution { + public boolean containsDuplicate(int[] nums) { + Set set = new HashSet<>(); + for (int i=0; i < nums.length; i++) { + if (!set.add(nums[i])) return true; + } + return false; + } +} From ab76aecb1da5c3b1a179e362b68cfbb73c1cbe84 Mon Sep 17 00:00:00 2001 From: juhui Date: Tue, 3 Mar 2026 23:32:56 +0900 Subject: [PATCH 2/4] WEEK 1 Solutions --- two-sum/juhui-jeong.java | 12 ++++++++++++ 1 file changed, 12 insertions(+) create mode 100644 two-sum/juhui-jeong.java diff --git a/two-sum/juhui-jeong.java b/two-sum/juhui-jeong.java new file mode 100644 index 0000000000..7e58044759 --- /dev/null +++ b/two-sum/juhui-jeong.java @@ -0,0 +1,12 @@ +class Solution { + public int[] twoSum(int[] nums, int target) { + for(int i = 0; i < nums.length; i++) { + for(int j=i+1; j < nums.length; j++) { + if (nums[i] + nums[j] == target) { + return new int[] {i, j}; + } + } + } + return new int[0]; + } +} From ce9b140c6ee39ae4552f4bfa4538329b59ca4516 Mon Sep 17 00:00:00 2001 From: juhui Date: Wed, 4 Mar 2026 22:13:01 +0900 Subject: [PATCH 3/4] WEEK 1 Solutions --- top-k-frequent-elements/juhui-jeong.java | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) create mode 100644 top-k-frequent-elements/juhui-jeong.java diff --git a/top-k-frequent-elements/juhui-jeong.java b/top-k-frequent-elements/juhui-jeong.java new file mode 100644 index 0000000000..a667388ec3 --- /dev/null +++ b/top-k-frequent-elements/juhui-jeong.java @@ -0,0 +1,24 @@ +class Solution { + public int[] topKFrequent(int[] nums, int k) { + Map map = new HashMap<>(); + + for (int i = 0; i< nums.length; i++) { + if (map.containsKey(nums[i])) { + map.put(nums[i], map.get(nums[i])+1); + } else { + map.put(nums[i], 1); + } + } + + List> entryList = new LinkedList<>(map.entrySet()); + entryList.sort(Map.Entry.comparingByValue(Collections.reverseOrder())); + + int[] result = new int[k]; + + for(int i =0; i < k; i++) { + result[i] = entryList.get(i).getKey(); + } + + return result; + } +} From 4f0c677c655111434d8f87d954cf50225246d514 Mon Sep 17 00:00:00 2001 From: juhui Date: Fri, 6 Mar 2026 20:08:26 +0900 Subject: [PATCH 4/4] WEEK 1 Solutions --- longest-consecutive-sequence/juhui-jeong.java | 25 +++++++++++++++++++ 1 file changed, 25 insertions(+) create mode 100644 longest-consecutive-sequence/juhui-jeong.java diff --git a/longest-consecutive-sequence/juhui-jeong.java b/longest-consecutive-sequence/juhui-jeong.java new file mode 100644 index 0000000000..b77d781ef1 --- /dev/null +++ b/longest-consecutive-sequence/juhui-jeong.java @@ -0,0 +1,25 @@ +class Solution { + public int longestConsecutive(int[] nums) { + if(nums == null || nums.length == 0) return 0; + Arrays.sort(nums); + + int maxLen = 1; + int curLen = 1; + + for(int i = 1; i < nums.length; i++) { + if (nums[i] == nums[i-1]) { + // 중복 건너뛰기 + continue; + } + + if (nums[i] == nums[i-1] +1) { + curLen++; + } else { + maxLen = Math.max(maxLen, curLen); + curLen = 1; + } + } + + return Math.max(maxLen, curLen); + } +}