solves first bad version

Author: anishLearnsToCode

src/FirstBadVersion.java

@@ -0,0 +1,17 @@
+public class FirstBadVersion {
+    public int firstBadVersion(int n) {
+        int left = 1, right = n, mid;
+        while (left <= right) {
+            mid = left + (right - left) / 2;
+            if (isBadVersion(mid) && !isBadVersion(mid - 1)) return mid;
+            else if (!isBadVersion(mid)) right = mid - 1;
+            else left = mid + 1;
+        }
+        return left;
+    }
+
+    // implemented by leetcode (just reference here)
+    private static boolean isBadVersion(int version) {
+        return false;
+    }
+}