Added task 2543

Author: javadev

README.md

@@ -1848,6 +1848,7 @@ implementation 'com.github.javadev:leetcode-in-java:1.21'
 
 | #    |      Title     | Difficulty  | Tag         | Time, ms | Time, %
 |------|----------------|-------------|-------------|----------|---------
+| 2543 |[Check if Point Is Reachable](src/main/java/g2501_2600/s2543_check_if_point_is_reachable/Solution.java)| Hard | Math, Number_Theory | 0 | 100.00
 | 2542 |[Maximum Subsequence Score](src/main/java/g2501_2600/s2542_maximum_subsequence_score/Solution.java)| Medium | Array, Sorting, Greedy, Heap_(Priority_Queue) | 94 | 84.75
 | 2541 |[Minimum Operations to Make Array Equal II](src/main/java/g2501_2600/s2541_minimum_operations_to_make_array_equal_ii/Solution.java)| Medium | Array, Math, Greedy | 3 | 100.00
 | 2540 |[Minimum Common Value](src/main/java/g2501_2600/s2540_minimum_common_value/Solution.java)| Easy | Array, Hash_Table, Binary_Search, Two_Pointers | 0 | 100.00

src/main/java/g2501_2600/s2543_check_if_point_is_reachable/Solution.java

@@ -0,0 +1,19 @@
+package g2501_2600.s2543_check_if_point_is_reachable;
+
+// #Hard #Math #Number_Theory #2023_05_11_Time_0_ms_(100.00%)_Space_39.3_MB_(70.37%)
+
+public class Solution {
+    public boolean isReachable(int x, int y) {
+        int g = gcd(x, y);
+        return (g & (g - 1)) == 0;
+    }
+
+    private int gcd(int x, int y) {
+        while (x != 0) {
+            int tmp = x;
+            x = y % x;
+            y = tmp;
+        }
+        return y;
+    }
+}

src/main/java/g2501_2600/s2543_check_if_point_is_reachable/readme.md

@@ -0,0 +1,34 @@
+2543\. Check if Point Is Reachable
+
+Hard
+
+There exists an infinitely large grid. You are currently at point `(1, 1)`, and you need to reach the point `(targetX, targetY)` using a finite number of steps.
+
+In one **step**, you can move from point `(x, y)` to any one of the following points:
+
+*   `(x, y - x)`
+*   `(x - y, y)`
+*   `(2 * x, y)`
+*   `(x, 2 * y)`
+
+Given two integers `targetX` and `targetY` representing the X-coordinate and Y-coordinate of your final position, return `true` _if you can reach the point from_ `(1, 1)` _using some number of steps, and_ `false` _otherwise_.
+
+**Example 1:**
+
+**Input:** targetX = 6, targetY = 9
+
+**Output:** false
+
+**Explanation:** It is impossible to reach (6,9) from (1,1) using any sequence of moves, so false is returned. 
+
+**Example 2:**
+
+**Input:** targetX = 4, targetY = 7
+
+**Output:** true
+
+**Explanation:** You can follow the path (1,1) -> (1,2) -> (1,4) -> (1,8) -> (1,7) -> (2,7) -> (4,7). 
+
+**Constraints:**
+
+*   <code>1 <= targetX, targetY <= 10<sup>9</sup></code>

src/test/java/g2501_2600/s2543_check_if_point_is_reachable/SolutionTest.java

@@ -0,0 +1,18 @@
+package g2501_2600.s2543_check_if_point_is_reachable;
+
+import static org.hamcrest.CoreMatchers.equalTo;
+import static org.hamcrest.MatcherAssert.assertThat;
+
+import org.junit.jupiter.api.Test;
+
+class SolutionTest {
+    @Test
+    void isReachable() {
+        assertThat(new Solution().isReachable(6, 9), equalTo(false));
+    }
+
+    @Test
+    void isReachable2() {
+        assertThat(new Solution().isReachable(4, 7), equalTo(true));
+    }
+}