41 lines
1.1 KiB
Markdown
41 lines
1.1 KiB
Markdown
> **4.** Suppose that the following declarations are in effect:
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```c
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struct point {int x, y; };
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struct rectangle { struct point upper_left, lower_right; };
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struct rectangle *p;
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```
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> Assume that we want `p` to point to a rectangle structure whose upper left corner is at $(10, 25)$, and whose lower right corner is at $(20, 15)$. Write a series of statements that allocate such a structure and initialize it as indicated.
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```c
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struct rectangle rect = { { 10, 25 }, { 20, 15 } };
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p = ▭
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```
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---
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> **5.** Suppose that `f` and `p` are declared as follows:
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```c
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struct {
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union {
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char a, b;
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int c;
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} d;
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int e[5];
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} f, *p = &f;
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```
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> Which of the following statements are legal?
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(a) `p->b = ' ';`
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(b) `p->e[3] = 10;` - **Legal**
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(c) `(*p).d.a = '*';` - **Legal**
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(d) `p->d->c = 20;`
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---
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> **7.** The following loop is supposed to delete all nodes from a linked list and release the memory that they occupy. Unfortunately, the loop is incorrect. Explain what's wrong with it and show how to fix the bug.
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```c
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for (p = first; p != NULL; p = p->next)
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free(p);
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```
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The above loop won't function because it deallocates an entry, resulting |