Create LeetCode_278_FirstBadVersion.java

Author: kn9012

250310/LeetCode_278_FirstBadVersion.java

@@ -0,0 +1,24 @@
+/* The isBadVersion API is defined in the parent class VersionControl.
+      boolean isBadVersion(int version); */
+
+public class Solution extends VersionControl {
+    public int firstBadVersion(int n) {
+        int left = 1;
+        int right = n;
+
+        int answer = -1;
+        
+        while (left <= right) {
+            int mid = right + (left - right) / 2;
+
+            if (isBadVersion(mid)) {
+                answer = mid;
+                right = mid - 1;
+            } else {
+                left = mid + 1;
+            }
+        }
+        
+        return answer;
+    }
+}