add 2103

Author: fishercoder1534

README.md

@@ -8,6 +8,7 @@ _If you like this project, please leave me a star._ ★
 
 |  #  |      Title     |   Solutions   | Video  | Difficulty  | Tag                  
 |-----|----------------|---------------|--------|-------------|-------------
+|2103|[Rings and Rods](https://leetcode.com/problems/rings-and-rods/)|[Java](../master/src/main/java/com/fishercoder/solutions/_2103.java) ||Easy||
 |2099|[Find Subsequence of Length K With the Largest Sum](https://leetcode.com/problems/find-subsequence-of-length-k-with-the-largest-sum/)|[Java](../master/src/main/java/com/fishercoder/solutions/_2099.java) ||Easy||
 |2095|[Delete the Middle Node of a Linked List](https://leetcode.com/problems/delete-the-middle-node-of-a-linked-list/)|[Java](../master/src/main/java/com/fishercoder/solutions/_2095.java) ||Medium||
 |2094|[Finding 3-Digit Even Numbers](https://leetcode.com/problems/finding-3-digit-even-numbers/)|[Java](../master/src/main/java/com/fishercoder/solutions/_2094.java) ||Easy||

src/main/java/com/fishercoder/solutions/_2103.java

@@ -0,0 +1,34 @@
+package com.fishercoder.solutions;
+
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+
+public class _2103 {
+    public static class Solution1 {
+        public int countPoints(String rings) {
+            Map<Integer, Set<Integer>> map = new HashMap<>();
+            for (int i = 0; i < rings.length() - 1; i += 2) {
+                char color = rings.charAt(i);
+                int pos = Character.getNumericValue(rings.charAt(i + 1));
+                Set<Integer> set = map.getOrDefault(pos, new HashSet<>());
+                if (color == 'R') {
+                    set.add(1);
+                } else if (color == 'G') {
+                    set.add(2);
+                } else {
+                    set.add(3);
+                }
+                map.put(pos, set);
+            }
+            int ans = 0;
+            for (int pos : map.keySet()) {
+                if (map.get(pos).size() == 3) {
+                    ans++;
+                }
+            }
+            return ans;
+        }
+    }
+}

src/test/java/com/fishercoder/_2103Test.java

@@ -0,0 +1,24 @@
+package com.fishercoder;
+
+import com.fishercoder.solutions._2103;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+public class _2103Test {
+    private static _2103.Solution1 solution1;
+    private static int expected;
+
+    @BeforeClass
+    public static void setup() {
+        solution1 = new _2103.Solution1();
+    }
+
+    @Test
+    public void test1() {
+        expected = 1;
+        assertEquals(expected, solution1.countPoints("B0B6G0R6R0R6G9"));
+    }
+
+}