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Author: programmer4229

Diff for: 3Sum.java

@@ -0,0 +1,44 @@
+class Solution {
+    public List<List<Integer>> threeSum(int[] nums) {
+        List<List<Integer>> result = new ArrayList<>();
+        Arrays.sort(nums);
+        if (nums.length == 3 && (nums[0] + nums[1] + nums[2]) == 0) {
+            result.add(new ArrayList<Integer>());
+            result.get(0).add(nums[0]);
+            result.get(0).add(nums[1]);
+            result.get(0).add(nums[2]);
+            return result;
+        }
+        for (int i = 0; i < nums.length - 2; i++) {
+            if (i == 0 || (i > 0 && nums[i] != nums[i-1])) {
+                int left = i+1;
+                int right = nums.length - 1;
+
+                while (right > left) {
+                    int threeSum = nums[i] + nums[left] + nums[right];
+                    if (threeSum > 0) {
+                        right--;
+                    } else if (threeSum < 0) {
+                        left++;
+                    } else {
+                        ArrayList<Integer> newL = new ArrayList<Integer>();
+                        newL.add(nums[i]);
+                        newL.add(nums[left]);
+                        newL.add(nums[right]);
+                        result.add(newL);
+                        while (left < right && nums[left] == nums[left + 1]) {
+                            left++;
+                        }
+                        while (nums[right] == nums[right - 1] && left < right) {
+                            right--;
+                        }
+                        left++;
+                        right--;
+                    }
+                }
+            }
+        }
+        return result;
+    }
+        
+}

Diff for: ContainerWater.java

@@ -0,0 +1,19 @@
+class Solution {
+    public int maxArea(int[] height) {
+        int l = 0;
+        int r = height.length - 1;
+        int maxArea = 0;
+        while (l < r) {
+            int area = ((r+1) - (l+1)) * Math.min(height[l],height[r]);
+            if (area > maxArea) {
+                maxArea = area;
+            } 
+            if (height[l] < height[r]) {
+                l = l + 1;
+            } else {
+                r = r - 1;
+            }
+        }
+        return maxArea;
+    }
+}

Diff for: GroupAnagram.java

@@ -0,0 +1,24 @@
+import java.util.Map;
+import java.util.ArrayList;
+
+class Solution {
+    public List<List<String>> groupAnagrams(String[] strs) {
+        Map<String, List<String>> map = new HashMap<>();
+
+        for (String word: strs) {
+            char[] chars = word.toCharArray();
+            Arrays.sort(chars);
+            String sorted = new String(chars);
+
+            if (map.containsKey(sorted)) {
+                map.get(sorted).add(word);
+            } else {
+                map.put(sorted, new ArrayList<>());
+                map.get(sorted).add(word);
+            }
+            
+        }
+
+        return new ArrayList<>(map.values());
+    }
+}

Diff for: ProductOfArrayExceptSelf.java

@@ -0,0 +1,17 @@
+class Solution {
+    public int[] productExceptSelf(int[] nums) {
+        int[] answers = new int[nums.length];
+        int left = 1;
+        int right = 1;
+        for (int i = 0; i < nums.length; i++) {
+            answers[i] = left;
+            left *= nums[i];
+        }
+        for (int i = nums.length - 1; i >= 0; i--) {
+            answers[i] *= right;
+            right *= nums[i];
+        }
+
+        return answers;
+    }
+}