[Java] : Binary Search Iterative/Recursive approach and some coding s…

…tyle changes (#13)

Co-authored-by: Ritabrata Nag <[email protected]>

binSearch/iterativeBinSearch.java

@@ -0,0 +1,40 @@
+/**
+ * Created by Ritabrata, 31/08/2024
+ */
+
+package Codes_contest.binSearch;
+
+import java.util.Scanner;
+
+public class iterativeBinSearch {
+    public static int binSearchIteration(int[] a, int n, int t) {
+        int low = 0;
+        int high = n - 1;
+        int mid = -1;
+        while (low <= high) {
+            mid = (low + high) / 2;
+            if (a[mid] == t) {
+                return mid;
+            } else if (t > a[mid]) {
+                low = mid + 1;
+            } else {
+                high = mid - 1;
+            }
+        }
+        return mid;
+    }
+
+    public static void main(String[] args) {
+        Scanner sc = new Scanner(System.in);
+        int n = sc.nextInt();
+        int[] a = new int[n];
+        for (int i = 0; i < n; i++) {
+            a[i] = sc.nextInt();
+        }
+        int target = sc.nextInt();
+        int index = binSearchIteration(a, n, target);
+        System.out.println((index != -1) ? "Target is found" : "Target is not found");
+        System.out.println("Target element is found at index : " + index);
+        sc.close();
+    }
+}

binSearch/recursiveBinSearch.java

@@ -0,0 +1,37 @@
+/**
+ * Created by Ritabrata, 31/08/2024
+ */
+
+
+package Codes_contest.binSearch;
+
+import java.util.Scanner;
+
+public class recursiveBinSearch {
+    public static int recursionOnArray(int[] a, int n, int target, int low, int high) {
+        if (low > high) {
+            return -1;
+        }
+        int mid = (low + high) / 2;
+        if (a[mid] == target) {
+            return mid;
+        } else if (a[mid] > target) {
+            return recursionOnArray(a, n, target, low, mid - 1);
+        } else {
+            return recursionOnArray(a, n, target, mid + 1, high);
+        }
+    }
+
+    public static void main(String[] args) {
+        Scanner sc = new Scanner(System.in);
+        int n = sc.nextInt();
+        int[] a = new int[n];
+        for (int i = 0; i < n; i++) {
+            a[i] = sc.nextInt();
+        }
+        int target = sc.nextInt();
+        int targetIndex = recursionOnArray(a, n, target, 0, n - 1);
+        System.out.println("Target element found at index : " + targetIndex);
+        sc.close();
+    }
+}

goodbye_2023_C.java

@@ -1,15 +1,18 @@
+package Codes_contest;
+
 import java.util.*;
 
 public class goodbye_2023_C {
     public static void main(String[] args) {
         Scanner sc = new Scanner(System.in);
         int t = sc.nextInt();
+        int n = sc.nextInt();
         // Input handling
         while(t --> 0){
             generateSquareNumbers(n);
         }
 
-        scanner.close();
+        sc.close();
     }
        static void generateSquareNumbers(int n) {
         int[] numbers = new int[n];

leetcode/2751-robot-collisions.java → leetcode/RobotCollisions.java

@@ -1,7 +1,7 @@
-package leetcode;
+package Codes_contest.leetcode;
 
 import java.util.*;
-class Solution {
+class RobotCollisions {
     class Robot{
         int position;
         int health;

leetcode/01-two-sum.java → leetcode/TwoSum.java

@@ -1,6 +1,6 @@
 package leetcode;
 import java.util.*;
-class Solution {
+class TwoSum {
     public int[] twoSum(int[] nums, int target) {
         int[] res = new int[2];
         HashMap<Integer,Integer> map = new HashMap<>();

leetcode_biweekly_121_C.java

@@ -22,5 +22,4 @@ static int helper(int x, int y, int minOperations, Queue<Integer> q){
         }
         return minOperations;
     }
-    public static void main(Str)
 }