---
title: 第一次作业（题目）
date: 2020-10-30 09:47:21
tags:
---


# 第一题

写出下列程序运行的结果：

```C
#include <stdio.h>

int main()
{
    int a, b;
    char c1, c2;
    float d, e;
    double f, g;
    long m, n;
    unsigned int p, q;
    a = 61; b = 62;
    c1 = 'a'; c2 = 'b';
    d = 3.56; e = -6.78;
    f = 3157.890121; g = 0.123456789;
    m = 50000; n = -60000;
    p = 32768; q = 4000;
    printf("sizeof: %d, a = %d, b = %d\n", sizeof(int), a, b);
    printf("sizeof: %d, c1 = %c, c2 = %c\n", sizeof(char), c1, c2);
    printf("sizeof: %d, d = %-6.2f, e = %-6.2f\n", sizeof(float), d, e);
    printf("sizeof: %d, f = %-15.6f, g = %-15.12f\n", sizeof(double), f, g);
    printf("sizeof: %d, m = %ld, n = %ld\n", sizeof(long), m, n);
    printf("sizeof: %d, p = %u, q = %u\n", sizeof(unsigned), p, q);
    return 0;
}
```

# 第二题

写出下列程序的运行结果：

```C
#include <stdio.h>

int main()
{
    int i, j, m, n;
    i = 8; j = 10;
    m = ++i; n = j++;
    printf("%d, %d, %d, %d\n", i, j, m, n);
    return 0;
}
```

# 第三题

求下面算术表达式的值：

|   #   | 表达式                                 | 变量的值                           |
| :---: | :------------------------------------- | :--------------------------------- |
|   1   | `3.5 + 1 / 2 + 56 % 10`                |                                    |
|   2   | `(a++ * 1 / 3)`                        | 设`a = 2`                          |
|   3   | `x + a % 3 * (int)(x + y) % 2 / 4`     | 设`x = 2.5, a = 7, y = 4.7`        |
|   4   | `(float)(a + b) / 2 + (int)x % (int)y` | 设a` = 2, b = 3, x = 3.5, y = 2.5` |
|   5   | `x = (x = ++y, x + 5, x / 5)`          | 设`x = 3, y = 4`                   |

# 第五题

写出下面表达式运算后`a`的值，设原来`a = 12`。

1. `a += a`
2. `a *= 2 + 3`
3. `a /= a + a`
4. `a += a -= a *= a`