1 files changed, 16 insertions, 0 deletions

diff --git a/12_interactive_problems/hidden_integer_3112.cpp b/12_interactive_problems/hidden_integer_3112.cpp
new file mode 100644
index 0000000..66e5a09
--- /dev/null
+++ b/12_interactive_problems/hidden_integer_3112.cpp
@@ -0,0 +1,16 @@
+#include <iostream>
+#include <string>
+
+int main() {
+        int m, l{0}, r{1000000000};
+        std::string s;
+        while (l+1 != r) {
+                m = (l+r)/2;
+                std::cout << "? " << m << std::endl;
+                std::cin >> s;
+                if (s == "YES") l = m;
+                else r = m;
+        }
+
+        std::cout << "! " << r << std::endl;
+}