From 6073a1f17c90381587948db5382089e2bbb2eab3 Mon Sep 17 00:00:00 2001
From: Muhammad Salah <67175615+MuhammadSalah-MS@users.noreply.github.com>
Date: Sat, 14 Jun 2025 16:48:29 +0300
Subject: [PATCH] Update setbits.c

follows the bit manipulation style (p as MSB of the field) as demonstrated in K&R, particularly aligning with the getbits example (p+1-n).
So bits to be set are the least after the  position p.
---
 chapter_2/exercise_2_06/setbits.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/chapter_2/exercise_2_06/setbits.c b/chapter_2/exercise_2_06/setbits.c
index b98b680..93d9c9c 100644
--- a/chapter_2/exercise_2_06/setbits.c
+++ b/chapter_2/exercise_2_06/setbits.c
@@ -28,8 +28,8 @@ unsigned int setbits(int x, int p, int n, int y)
 {
   ++p; // First position is 0
 
-  unsigned int mask1 = (~(~(~0 << n) << p) & x);
-  unsigned int mask2 = (~(~0 << n) & y) << p;
+  unsigned int mask1 = (~(~(~0 << n) << (p-n)) & x);
+  unsigned int mask2 = (~(~0 << n) & y) << (p-n);
 
   return mask1 | mask2;
 }