@@ -0,0 +1,32 @@
+'''
+1. 아이디어:
+이진탐색으로 풀이.
+2. 시간복잡도:
+o(log n)
+3. 알고리즘:
+이진탐색
+'''
+
+# The guess API is already defined for you.
+# @param num, your guess
+# @return -1 if num is higher than the picked number
+#          1 if num is lower than the picked number
+#          otherwise return 0
+# def guess(num: int) -> int:
+
+class Solution:
+    def guessNumber(self, n: int) -> int:
+        current = n // 2 + 1
+
+        # while True:
+        while True:
+            # print(current)
+            g = guess(current)
+
+            if g == -1:
+                n = current
+                current = n // 2
+            elif g == 1:
+                current = (n + current + 1) // 2
+            else:
+                return current