practice session

Author: Rohithv07

CodeForces/Contests/CodeforceContestes/src/contests/AdjacentXOR.java

@@ -0,0 +1,51 @@
+package contests;
+
+import java.util.Scanner;
+
+/**
+ * @author rohithvazhathody
+ * 15-Aug-2025
+ */
+public class AdjacentXOR {
+
+	/**
+	 * @param args
+	 */
+	public static void main(String[] args) {
+		Scanner sc = new Scanner(System.in);
+		int test = sc.nextInt();
+		while (test-- > 0) {
+			int n = sc.nextInt();
+			int [] nums1 = new int[n];
+			int [] nums2 = new int [n];
+			for (int index = 0; index < n; index++) {
+				nums1[index] = sc.nextInt();
+			}
+			for (int index = 0; index < n; index++) {
+				nums2[index] = sc.nextInt();
+			}
+			System.out.println(isConversionPossible(nums1, nums2, n));
+		}
+		sc.close();
+	}
+
+	private static String isConversionPossible(int[] nums1, int[] nums2, int n) {
+		for (int index = 0; index + 1 < n; index++) {
+			if ((nums1[index] ^ nums1[index + 1]) == nums2[index]) {
+				nums1[index] = nums2[index];
+			}
+		}
+		for (int index = n - 2; index >= 0; index--) {
+			if ((nums1[index] ^ nums1[index + 1]) == nums2[index]) {
+				nums1[index] = nums2[index];
+			}
+		}
+		for (int index = 0; index < n; index++) {
+			if (nums1[index] != nums2[index]) {
+				return "NO";
+			}
+		}
+		return "YES";
+	}
+
+}

CodeForces/Contests/CodeforceContestes/src/contests/ArborisContractio.java

@@ -0,0 +1,62 @@
+package contests;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Scanner;
+
+/**
+ * @author rohithvazhathody 15-Aug-2025
+ */
+public class ArborisContractio {
+
+	/**
+	 * @param args
+	 */
+	public static void main(String[] args) {
+		Scanner sc = new Scanner(System.in);
+		int test = sc.nextInt();
+		while (test-- > 0) {
+			int n = sc.nextInt();
+			List<List<Integer>> graph = new ArrayList<>();
+			for (int index = 0; index < n; index++) {
+				graph.add(new ArrayList<>());
+			}
+			for (int index = 0; index < n - 1; index++) {
+				int u = sc.nextInt();
+				int v = sc.nextInt();
+				u--;
+				v--;
+				graph.get(u).add(v);
+				graph.get(v).add(u);
+			}
+			System.out.println(findMinOperation(graph, n));
+		}
+		sc.close();
+	}
+
+	private static int findMinOperation(List<List<Integer>> graph, int n) {
+		int totalLeaf = 0;
+		for (int index = 0; index < n; index++) {
+			if (graph.get(index).size() == 1) {
+				totalLeaf++;
+			}
+		}
+		int totalOperation = Integer.MAX_VALUE;
+		for (int index = 0; index < n; index++) {
+			// if already leaf, minus 1
+			int currentOperation = totalLeaf;
+			if (graph.get(index).size() == 1) {
+				currentOperation--;
+			}
+			List<Integer> children = graph.get(index);
+			for (Integer child : children) {
+				if (graph.get(child).size() == 1) {
+					currentOperation--;
+				}
+			}
+			totalOperation = Math.min(totalOperation, currentOperation);
+		}
+		return totalOperation;
+	}
+
+}