这两天复习RenMian给我留下谭浩强的C语言教程，温故而知新，夯实基础知识，
把谭浩强版C语言的第十二章《位运算》的书复习后把所有的编程习题做了一遍，贴出来激励自己一下，也希望有用的同学可以参考，时间和水平有限，不足之处，恳请读者批评指正
第十二章《位运算》答案如下
inc/testBits.h
01.unsigned short getbits(unsigned short value, int n1, int n2)
02.{
03. unsigned short usRet = 0, usTemp = 0, usMask = 0;
04.
05. usTemp = value >> n1;
06. usMask = ~( ~0 << (n2 – n1 + 1));
07.
08. usRet = usTemp & usMask;
09.
10. return usRet;
11.}
12.
13.short getComplement(short n)
14.{
15. short sRet = 0;
16.
17. if (n >= 0)
18. {
19. sRet = n;
20. }
21. else
22. {
23. sRet = -n;
24. sRet = ~sRet;
25. sRet = sRet + 1;
26. }
27.
28. return sRet;
29.}
30.
31.unsigned short move(unsigned short value, int n)
32.{
33. unsigned short usTemp = 0, usDest = 0;
34.
35. assert(n != 0);
36.
37. if (n > 0)
38. {
39. usTemp = value << (16 -n);
40. usDest = value >> n;
41. }
42. else
43. {
44. n = -n;
45.
46. usTemp = value >> (16 – n);
47. usDest = value << n;
48. }
49.
50. usDest = usDest | usTemp;
51. return usDest;
52.}
53.
54.int test_12_1()
55.{
56. unsigned short usRet = 0;
57. usRet = getbits(0x83BD, 4, 7);
58.
59. if (usRet == 0xB)
60. {
61. printf(“Test_12_1 Passed! \r\n”);
62. return 0;
63. }
64.
65. return 1;
66.}
67.
68.int test_12_2()
69.{
70. int ite = 0, iRet = 0;
71. unsigned short usDest = 0, usSrc = 0xFFFF, usMask = 0;
72.
73. for(ite = 0; ite < 16; ite += 2)
74. {
75. usMask = 1 << ite;
76. usDest = usDest | (usSrc & usMask);
77. }
78.
79. if (usDest == 0x5555)
80. {
81. printf(“Test_12_2 Passed! \r\n”);
82. return 0;
83. }
84.
85. return 1;
86.}
87.
88.int test_12_4()
89.{
90. unsigned short usDest1 = 0, usDest2 = 0, usSrc = 0xFFF7;
91.
92. usDest1 = move(0xFFF7, 4);
93. usDest2 = move(0xFFF7, -4);
94.
95. if (usDest1 == 0x7FFF && usDest2 == 0xFF7F)
96. {
97. printf(“Test_12_4 Passed! \r\n”);
98. return 0;
99. }
100. return 1;
101.}
102.
103.int test_12_5()
104.{
105. short sDest = 0, sSrc = -10;
106.
107. sDest = getComplement(sSrc);
108.
109. if (sDest == 0xFFFFFFF6)
110. {
111. printf(“Test_12_5 Passed! \r\n”);
112. return 0;
113. }
114.
115. return 1;
116.}
117.
118.
119.int testBits()
120.{
121. int iRet = 0;
122.
123. iRet += test_12_1();
124. iRet += test_12_2();
125. iRet += test_12_4();
126. iRet += test_12_5();
127.
128. return iRet;
129.}
src/main.cc
01.#include <stdio.h>
02.#include <stdlib.h>
03.#include <assert.h>
04.
05.#include “../inc/testFile.h”
06.#include “../inc/testBits.h”
07.
08.int main()
09.{
10. int iRet = 0;
11.
12.#if 0
13. iRet += testFile();
14. assert(iRet == 0);
15.#endif
16.
17. iRet += testBits();
18. assert(iRet == 0);
19.
20. return 0;
21.}
本文来自CSDN博客，转载请标明出处：http://blog.csdn.net/asiainfolf/archive/2011/03/19/6261765.aspx
