add 3206

Author: fishercoder1534

paginated_contents/algorithms/4th_thousand/README.md

@@ -1,5 +1,6 @@
 | #    | Title                                                                                                                                                               | Solutions                                                                                                                         | Video                                                                         | Difficulty | Tag                                                                  
 |------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------|------------|----------------------------------------------------------------------
+| 3206 | [Alternating Groups I](https://leetcode.com/problems/alternating-groups-i/) | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/fourththousand/_3206.java) |                                                                               | Easy       |
 | 3200 | [Maximum Height of a Triangle](https://leetcode.com/problems/maximum-height-of-a-triangle/) | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/fourththousand/_3200.java) |                                                                               | Easy       |
 | 3199 | [Count Triplets with Even XOR Set Bits I](https://leetcode.com/problems/count-triplets-with-even-xor-set-bits-i/) | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/fourththousand/_3199.java) |                                                                               | Easy       |
 | 3196 | [Maximize Total Cost of Alternating Subarrays](https://leetcode.com/problems/maximize-total-cost-of-alternating-subarrays/) | [Java](https://github.com/fishercoder1534/Leetcode/blob/master/src/main/java/com/fishercoder/solutions/fourththousand/_3196.java) |                                                                               | Medium     |DP

src/main/java/com/fishercoder/solutions/firstthousand/_3206.java

@@ -0,0 +1,26 @@
+package com.fishercoder.solutions.firstthousand;
+
+public class _3206 {
+    public static class Solution1 {
+        public int numberOfAlternatingGroups(int[] colors) {
+            int result = 0;
+            int len = colors.length;
+            for (int i = 0; i < len; i++) {
+                if (i == 0) {
+                    if (colors[i] != colors[len - 1] && colors[i] != colors[i + 1]) {
+                        result++;
+                    }
+                } else if (i < len - 1) {
+                    if (colors[i] != colors[i - 1] && colors[i] != colors[i + 1]) {
+                        result++;
+                    }
+                } else {
+                    if (colors[i] != colors[i - 1] && colors[i] != colors[0]) {
+                        result++;
+                    }
+                }
+            }
+            return result;
+        }
+    }
+}