From 1a0f57746d185684551358a35bb6d58b6b575810 Mon Sep 17 00:00:00 2001
From: Richard Qin <richard.qin.x@gmail.com>
Date: Sun, 20 Sep 2026 22:23:31 +0800
Subject: logtwo

---
 bits.c | 23 ++++++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/bits.c b/bits.c
index 7e0ed68..8652b1a 100644
--- a/bits.c
+++ b/bits.c
@@ -67,7 +67,28 @@ int samesign(int x, int y) {
  *   Difficulty: 4
  */
 int logtwo(int v) {
-    return 2;
+    int r = 0;
+    int s;
+
+    s = (v > 0xFFFF) << 4;
+    v = v >> s;
+    r = r | s;
+
+    s = (v > 0xFF) << 3;
+    v = v >> s;
+    r = r | s;
+
+    s = (v > 0xF) << 2;
+    v = v >> s;
+    r = r | s;
+
+    s = (v > 0x3) << 1;
+    v = v >> s;
+    r = r | s;
+
+    r = r | (v >> 1);
+
+    return r;
 }
 
 /*
-- 
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