CSAPP 第二章 课程作业

2.58

typedef unsigned char *byte_pointer;

int is_little_endian(int x = 1)
{
    byte_pointer y = (byte_pointer)&x;
    return !!y[0];
}```
## 2.62
```cpp
int int_shifts_are_arithmetic()
{
    int x = -1;
    int y = (x << 1) >> 1;
    return x == y;
}

2.74

int tsub_ok(int x, int y)
{
    if(y == -y && y != 0)
        return x > 0;
    y = -y;
    int sum = x + y;
    bool pos_over = x >= 0 && y >= 0 && sum < 0;
    bool neg_over = x < 0 && y < 0 && sum >= 0;
    return !(pos_over || neg_over);
}

2.77

A

$x<<4+x$

B

$x-x<<3$

C

$x<<6-x<<2$

D

$x<<4-x<<7$

2.85

A

E = 2, M = 1.11, f = 11, V = 7.0

B

E = n, M = 1.[1]···, f = [1]···, V = $2^{n+1}-1$

C

E = $2^{k-1}-2$, M = 1, f = 0, V = $2^{2^{k-1}-2}$

2.91

A

11.0010010000111111011011

B

11.[001]···