feat: 2025-10-28打卡

278.first-bad-version.java

@@ -0,0 +1,26 @@
+/*
+ * @lc app=leetcode id=278 lang=java
+ *
+ * [278] First Bad Version
+ */
+
+// @lc code=start
+/* 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 l = 1, r = n, m;
+        while(l < r) {
+            m = l + (r-l)/2;
+            if(isBadVersion(m)) {
+                r = m;
+            } else {
+                l = m + 1;
+            }
+        }
+        return l;
+    }
+}
+// @lc code=end
+