Tracy像太阳

题目： Write a C expression that will yield a word consisting of the least significant byte of x, and the remaining bytes of y. For operands x = 0x89ABCDEF and y = 0x76543210, this would give 0x765432E

低位存放在高地址，高位存放在低地址。

/* Get most significant byte from x */int get_msb(int x) {/* Shift by w-8 */int shift_val = (sizeof(int)-1)<<3;/* Arithmetic shift */int xright = x >> shift_val;/* Zero all but LSB */return xrig

#include #include #include /*如果 x 所有位都为 1 ，返回 1 ，否则，返回 0 */bool x_equals_1(int x) { return !(~x);}/*如果 x 所有位都为 0 ，返回 1 ，否则，返回 0 */bool x_equals_0(int x) { return !x;}/*如果 x 的最低

#include <stdio.h>#include <stdlib.h>#include <string.h>/* Return 1 when x contains an odd number of 1s; 0 otherwise.Assume w=32. */int odd_ones(unsigned x){ int y = x; int count_ones = 0;

#include <stdio.h>#include <stdlib.h>#include <string.h>/** Generate mask indicating leftmost 1 in x. Assume w=32.* For example 0xFF00 -> 0x8000, and 0x6600 --> 0x4000.* If x = 0, then return 0.*