interview problems: trees

src/extra_interview_problems/bitwise/set_bit.py

@@ -0,0 +1,30 @@
+#!/usr/bin/env python
+
+__author__ = "bt3"
+
+
+
+''' Set a bit in a binary number:
+    1) Shifts 1 over by i bits
+    2) make an OR with the number, only the value at bit i will change and all the others bit
+    of the mask are zero so will not affect the num
+
+'''
+
+
+
+def set_bit(num, i):
+    mask = 1 << i
+    return bin( num | mask )
+
+
+
+
+if __name__ == '__main__':
+    num = int('0100100', 2)
+    print set_bit(num, 0)   #'0b100101'
+    print set_bit(num, 1)   #'0b100110'
+    print set_bit(num, 2)   # nothing change '0b100100'
+    print set_bit(num, 3)   #'0b101100'
+    print set_bit(num, 4) #'0b110100'
+    print set_bit(num, 5)     # nothing change '0b100100'