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Author: coderpheonix

278. First Bad Version.cpp

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+// The API isBadVersion is defined for you.
+// bool isBadVersion(int version);
+
+class Solution {
+public:
+    int firstBadVersion(int n) {
+        int left = 1, right = n;
+
+        while (left < right)
+        { // Stop when left == right
+            int mid = left + (right - left) / 2;
+
+            if (isBadVersion(mid))
+            {
+                right = mid; // First bad version is at mid or before
+            }
+            else
+            {
+                left = mid + 1; // Search in the right half
+            }
+        }
+
+        return left; // Left now points to the first bad version
+    }
+};