Valid parentheses code

Java/containerWithMostWater.java

@@ -0,0 +1,49 @@
+import java.util.*;
+import java.util.Scanner;
+
+public class ContainerWithMostWater {
+
+    public static void main(String[] args) {
+
+        Scanner sc = new Scanner(System.in);
+
+        // Get inputs
+        System.out.println("Enter the number of lines:");
+        int n = sc.nextInt();
+
+        int[] height = new int[n];
+        System.out.println("Enter the heights of the lines:");
+        for (int i = 0; i < n; i++) {
+            height[i] = sc.nextInt();
+        }
+
+        int maxArea = findMaxArea(height);
+
+        System.out.println("The maximum water that can be contained is: " + maxArea);
+    }
+
+
+    public static int findMaxArea(int[] height) {
+        int left = 0;
+        int right = height.length - 1;
+        int maxArea = 0;
+
+        while (left < right) {
+            int width = right - left;
+            int minHeight = Math.min(height[left], height[right]);
+            int area = width * minHeight;
+
+            maxArea = Math.max(maxArea, area);
+
+            // Move the pointer pointing to the smaller line
+            if (height[left] < height[right]) {
+                left++;
+            } else {
+                right--;
+            }
+        }
+
+        return maxArea;
+    }
+}
+

Java/twoSum.java

@@ -0,0 +1,44 @@
+package twosum;
+
+import java.util.Scanner;
+
+public class twoSum {
+
+    public static void main(String[] args) {
+
+        Scanner sc = new Scanner(System.in);
+
+        // Get inputs
+        System.out.println("Enter the size of the array:");
+        int n = sc.nextInt();
+
+        int[] arr = new int[n];
+        System.out.println("Enter " + n + " integers:");
+        for (int i = 0; i < n; i++) {
+            arr[i] = sc.nextInt();
+        }
+
+        System.out.println("Enter the target sum:");
+        int target = sc.nextInt();
+
+        boolean found = false;
+
+        // Find two numbers that add up to target
+        for (int i = 0; i < n; i++) {
+            for (int j = i + 1; j < n; j++) {
+                if (arr[i] + arr[j] == target) {
+                    System.out.println("Two numbers found at indices " + i + " and " + j);
+                    System.out.println("Numbers are: " + arr[i] + " + " + arr[j] + " = " + target);
+                    found = true;
+                    break;
+                }
+            }
+            if (found) break;
+        }
+
+        if (!found) {
+            System.out.println("No two numbers found with the given target sum.");
+        }
+    }
+}
+

Java/validParentheses.java

@@ -0,0 +1,46 @@
+import java.util.Scanner;
+import java.util.Stack;
+
+public class validParentheses {
+
+    public static void main(String[] args) {
+
+        Scanner sc = new Scanner(System.in);
+
+        // Get input
+        System.out.println("Enter a string of brackets:");
+        String str = sc.nextLine();
+
+        boolean isValid = checkValidParentheses(str);
+
+        if (isValid) {
+            System.out.println("The parentheses are valid!");
+        } else {
+            System.out.println("The parentheses are NOT valid!");
+        }
+    }
+
+
+    public static boolean checkValidParentheses(String s) {
+        Stack<Character> stack = new Stack<>();
+
+        for (char ch : s.toCharArray()) {
+            if (ch == '(' || ch == '{' || ch == '[') {
+                stack.push(ch);
+            } else if (ch == ')' || ch == '}' || ch == ']') {
+                if (stack.isEmpty()) return false;
+
+                char top = stack.pop();
+
+                if ((ch == ')' && top != '(') ||
+                    (ch == '}' && top != '{') ||
+                    (ch == ']' && top != '[')) {
+                    return false;
+                }
+            }
+        }
+
+        return stack.isEmpty();
+    }
+}
+