第三次作业题目和答案(未公布)

source/_posts/homework1.md

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+---
+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`