diff --git a/c/374-guess-number-higher-or-lower.c b/c/374-guess-number-higher-or-lower.c
new file mode 100644
index 000000000..7ac0b9c11
--- /dev/null
+++ b/c/374-guess-number-higher-or-lower.c
@@ -0,0 +1,21 @@
+/*
+I pick a number from 1 to n. You have to guess which number I picked.
+
+Space: O(1)
+Time: O(log(n))
+*/
+
+long guess_bis(long min, long max){
+    long m = (max+min)/2;
+    int tmp = guess(m);
+    if (tmp==0)
+        return m;
+    else if (tmp<0)
+        return guess_bis(min,m-1);
+    else
+        return guess_bis(m+1,max);    
+}
+
+long guessNumber(long n){
+	return guess_bis(0,n);
+}