[sort colors && 3 sum && max container]

Sample.java

@@ -4,4 +4,103 @@
 // Any problem you faced while coding this :
 
 
-// Your code here along with comments explaining your approach
+// Your code here along with comments explaining your approach
+
+public class Sample {
+    // Time Complexity : O(n)
+    // Space Complexity : O(1)
+    // Did this code successfully run on Leetcode : yes
+    public void sortColors(int[] nums) {
+        int low = 0, mid = 0, high = nums.length - 1;
+        while (mid <= high) {
+            if (nums[mid] == 0) {
+                // swap
+                int temp = nums[low];
+                nums[low] = nums[mid];
+                nums[mid] = temp;
+                mid++;
+                low++;
+
+            } else if (nums[mid] == 1) {
+                mid++;
+            } else {
+                int temp = nums[high];
+                nums[high] = nums[mid];
+                nums[mid] = temp;
+                high--;
+            }
+        }
+    }
+    // Time Complexity : O(n^2)
+    // Space Complexity : O(1)
+    // Did this code successfully run on Leetcode : yes
+
+    public List<List<Integer>> threeSum(int[] nums) {
+        List<List<Integer>> result = new ArrayList<>();
+        Arrays.sort(nums);
+
+        for (int i = 0; i < nums.length && nums[i] <= 0 ; i++) {
+
+            if (i > 0 && nums[i] == nums[i - 1]) {
+                continue;
+            }
+
+            int left = i + 1;
+            int right = nums.length - 1;
+
+            while (left < right) {
+                int sum = nums[i] + nums[left] + nums[right];
+
+                if (sum == 0) {
+                    result.add(Arrays.asList(nums[i], nums[left], nums[right]));
+
+                    while (left < right && nums[left] == nums[left + 1]) {
+                        left++;
+                    }
+
+                    while (left < right && nums[right] == nums[right - 1]) {
+                        right--;
+                    }
+
+                    left++;
+                    right--;
+                }
+                else if (sum < 0) {
+                    left++;
+                }
+                else {
+                    right--;
+                }
+            }
+        }
+
+        return result;
+    }
+
+    // Time Complexity : O(n)
+    // Space Complexity : O(1)
+    // Did this code successfully run on Leetcode : yes
+    public int maxArea(int[] height) {
+        int left = 0;
+        int right = height.length - 1;
+        int max = 0;
+
+        while (left < right) {
+            int width = right - left;
+            int h = Math.min(height[left], height[right]);
+            int area = width * h;
+
+            max = Math.max(max, area);
+
+            if (height[left] < height[right]) {
+                left++;
+            } else {
+                right--;
+            }
+        }
+
+        return maxArea;
+    }
+
+
+}