add 2220

Author: fishercoder1534

README.md

@@ -8,6 +8,7 @@ _If you like this project, please leave me a star._ ★
 
 | #    |      Title     | Solutions                                                                                                                                | Video                                                                         | Difficulty  | Tag                  
 |------|----------------|------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------|-------------|-------------
+| 2220 |[Minimum Bit Flips to Convert Number](https://leetcode.com/problems/minimum-bit-flips-to-convert-number/)| [Java](../master/src/main/java/com/fishercoder/solutions/_2220.java)                                                                     || Easy                                                                          ||
 | 2215 |[Find the Difference of Two Arrays](https://leetcode.com/problems/find-the-difference-of-two-arrays/)| [Java](../master/src/main/java/com/fishercoder/solutions/_2215.java)                                                                     || Easy                                                                          ||
 | 2210 |[Count Hills and Valleys in an Array](https://leetcode.com/problems/count-hills-and-valleys-in-an-array/)| [Java](../master/src/main/java/com/fishercoder/solutions/_2210.java)                                                                     || Easy                                                                          ||
 | 2208 |[Minimum Operations to Halve Array Sum](https://leetcode.com/problems/minimum-operations-to-halve-array-sum/)| [Java](../master/src/main/java/com/fishercoder/solutions/_2208.java)                                                                     || Medium                                                                          ||

src/main/java/com/fishercoder/solutions/_2220.java

@@ -0,0 +1,19 @@
+package com.fishercoder.solutions;
+
+public class _2220 {
+    public static class Solution1 {
+        public int minBitFlips(int start, int goal) {
+            String sBin = Integer.toBinaryString(start);
+            String s = String.format("%32s", sBin).replaceAll(" ", "0");
+            String gBin = Integer.toBinaryString(goal);
+            String g = String.format("%32s", gBin).replaceAll(" ", "0");
+            int ans = 0;
+            for (int i = 0; i < s.length(); i++) {
+                if (s.charAt(i) != g.charAt(i)) {
+                    ans++;
+                }
+            }
+            return ans;
+        }
+    }
+}

src/test/java/com/fishercoder/_2220Test.java

@@ -0,0 +1,22 @@
+package com.fishercoder;
+
+import com.fishercoder.solutions._2220;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+public class _2220Test {
+    private static _2220.Solution1 solution1;
+
+    @BeforeClass
+    public static void setup() {
+        solution1 = new _2220.Solution1();
+    }
+
+    @Test
+    public void test1() {
+        assertEquals(3, solution1.minBitFlips(10, 7));
+    }
+
+}