[理工] [DS] 程式

[amidofun ()]

請高手幫我看看答案對不對

解救我的指標吧

有心有好報

7.Write the output of the following program. (8%)

int a, b;
for (a=1, b=1; a<=100; a++) {
        if (b>=18) break;
        if (b%3==1) {
          b+=2;
          continue;
        }
        b++;
        printf("b = %d\n", b);
}
printf("a = %d", a);
===================================================
OUTPUT: b = 4
        b = 7
        b = 10
        b = 13
        b = 16
        b = 19
        a = 6
===================================================

8.Write the output of the following program. (8%)

void add(int x, int* y, int* w, int **p)
{
     static int z = 2;
     *w = z++;
     x++; y++; (*p)++;
}

int main(void)
{
        int a[] = { 2, 4, 6, 8, 10, 12, 14 };
        int i, x = 5, *y = a+1, z = 0, *q = a+2;
        int **p = &q;
        for (i=0; i<3; i++) {
                add(x, y, &z, p);
                printf("%d, %d, %d, %d\n", x, *y, z, *q);
        }
        return 0;
}
======================================================
OUTPUT:卡住  指標好難阿  請高手指教
======================================================

9. Write the output of the following program. (6%)

#define M(a,b) a*b
int main(void)
{
        int i = 5, j = 6;
        printf(”i*j = %d”, M(i+2, j-2*2));
        return 0;
}
======================================================
OUTPUT: i*j = 14
======================================================

10. Rewrite and correct the following program. (8%)

include [stdio.h]
int main(void)
{
        int i=1, j=5
        If (i < j)
                i++; j--;
        else /* i >= j
        printf(”% >= %”, &i, &j);
        return 0;
}
======================================================
OUTPUT: 3 >= 3
======================================================

11. Which could be the second line of the program? (multiple-choice, more
    than one answer) (6%)

   int i=1, j=2;
(a) int *p[2] = {&i, &j};
(b) int (*p)[2] = {&i, &j};
(c) int* p[2] = {&i, &j};
(d) int p[2] = {&i, &j};
======================================================
ANS: 又是指標  卡住
======================================================

12. Which are NOT the keywords in C? (multiple-choice, more than one answer)
    (6%)
(a) which (b) void
(c) until (d) signed
(e) static (f) then
======================================================
ANS:(a)
======================================================

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◆ From: 218.32.102.8
推 assassin88:只看了第七題..就覺得你錯很大= ="
※ 編輯: amidofun        來自: 218.32.102.8         (03/20 17:15)
→ amidofun:拍謝   少貼一行
※ 編輯: amidofun        來自: 218.32.102.8         (03/20 17:16)
推 assassin88:喔喔 那第七就沒錯 其實看&前 你要先搞懂 call by valu
→ assassin88:e/call by address 這兩種概念
→ amidofun:z=0  那&z是位址吧  但我不知道要傳啥
→ amidofun:第一輪x=6 z=3??  *y和*q我就看不懂了
→ amidofun:x三輪都是5?
推 soldier723:第八題題目有沒有打錯呀?
※ 編輯: amidofun        來自: 218.32.102.8         (03/20 22:36)
→ amidofun:sorry  以修正
→ amidofun:拍謝   少一行
推 soldier723:5,4,2,8 ; 5,4,3,10 ; 5,4,4,12 我丟到C裡面去跑的= =