电子科大计算机复试C语言

复试终于结束了，唉。。一言难尽

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
void test1_1_swap(char *pa, char *pb)
{
    //由于传入的实参是数组地址，它是一个char* const类型，
    //即数组的首地址是无法被修改的，所以这种直接交换首地址的方法是不可行的
    //char *temp;
    //temp = pa;
    //pa = pb;
    //pb = temp;
    char temp[100];
    strcpy(temp, pa);
    strcpy(pa, pb);
    strcpy(pa, temp);
}

void test1_2()
{
    char pa[] = "ABCDE";
    char *pb = "EFG";
    //pb[1] = 'A';//pb指向字符串常量(const char*），不能修改字符串常量的内容
    pb = pa;
    //strcpy(pa, "ABCDEFGXYZ");//pa的内存空间只有6B，而被复制的字符串大小为11B
    pb = "D";
}

void test2_1(char item)
{
    //item = 'F'；
    //如果item没有存在于arr中，那么程序将死循环
    char arr[] = "ABCDE";
    int N = strlen(arr) - 1, num;
    //for(num = N; arr[num] != item; num--);
    for(num = N; arr[num] != item && num >= 0; num--);
    printf("test2_1::num = %d\n", num);
}

int test2_2_value(int n)
{
    // n = 4;
    // 输入11, 22, 33, 44
    // 输出110 = 44 + 33 + 22 + 11
    int x;
    if(n == 0)
    {
        return 0;
    }
    else
    {
        scanf("%d", &x);
        return(test2_2_value(n - 1) + x);
    }
}

void test2_3()
{
    char a[] = "ABC";

    //1、值传递
    //void fun1(char e);
    //fun1(a[0]);

    //2、地址传递

    //形参为指针
    //void fun2_1(char* pa, int n);
    //fun2_1(a, strlen(a));

    //形参为数组
    //void fun2_2(char aa[], int n);
    //fun2_2(&a[0], strlen(a));
    //或
    //fun2_2(a, strlen(a));
}

void test2_4()
{
    //s;
    //loop:
    //if(B)
    //{
    //s;
    //goto loop;
    //}
    //else
    //{
    //end;
    //}
}

void test3_1_main()
{
    long a1, a2, b1, b2, c1, c2;
    char op;
    printf("\ntest3_1::请输入要进行的分数运算:");
    scanf("%ld/%ld%c%ld/%ld", &a1, &a2, &op, &b1, &b2);
    if(0 == a2 || 0 == b2)
    {
        printf("test3_1::分母不能为零\n");
        return;
    }
    switch(op)
    {
    case '+':
        c1 = a1 * b2 + b1 * a2;
        c2 = a2 * b2;
        break;
    case '-':
        c1 = a1 * b2 - b1 * a2;
        c2 = a2 * b2;
        break;
    case '*':
        c1 = a1 * b1;
        c2 = a2 * b2;
        break;
    case '/':
        c1 = a1 * b2;
        c2 = a2 * b1;
        break;
    default:
        printf("test3_1::不支持该运算符\n");
        return;
    }
    long test3_1_gcd(long c1, long c2);
    long g = test3_1_gcd(c1, c2);
    c1 = c1 / g;
    c2 = c2 / g;
    printf("test3_1::%ld/%ld\n", c1, c2);
}


long test3_1_gcd(long c1, long c2)
{
    if(c1 < c2)
    {
        long temp = c1;
        c1 = c2;
        c2 = temp;
    }
    long r = c1 % c2;
    while(r != 0)
    {
        c1 = c2;
        c2 = r;
        r = c1 % c2;
    }
    return c2;
}

struct node
{
    int num;
    struct node *next;
};
void test3_2_main()
{

    void test3_2_turn(struct node **head);
    struct node *head, *p;
    head = (struct node*)malloc(sizeof(struct node));
    head->num = 0;
    head->next = NULL;
    int i;
    for(i = 10; i > 0; --i)
    {
        p = (struct node*)malloc(sizeof(struct node));
        p->num = i;
        p->next = head->next;
        head->next = p;
    }
    p = head;
    printf("test3_2::");
    while(p)
    {
        printf("%d ", p->num);
        p = p->next;
    }
    printf("\n");
    //printf("%5x\n", (int)head);
    test3_2_turn(&head);
    //printf("%5x\n", (int)head);
    printf("test3_2::");
    while(head)
    {
        printf("%d ", head->num);
        p = head;
        head = head->next;
        free(p);
    }
}

void test3_2_turn(struct node **phead)
{
    struct node temp, *head = *phead;
    temp.next = NULL;
    struct node *p = head->next;
    while(head)
    {
        p = head->next;
        head->next = temp.next;
        temp.next = head;
        head = p;
    }
    *phead = temp.next;
}

void test3_3_main()
{
    char num[50];
    int count[10];
    int i, j;
    for(i = 0; i < 10; ++i)
    {
        count[i] = 0;
    }
    printf("\ntest3_3::请输入数字串:");
    scanf("%s", num);
    for(i = 0; num[i] != '\0'; ++i)
    {
        j = (int)(num[i] - '0');
        ++count[j];
    }
    printf("test3_3::");
    for(i = 0; i < 10; ++i)
    {
        printf("%2d:%2d ", i, count[i]);
    }
    printf("\n");
}

struct student
{
    int no;
    int c_score;
};
#define S_MAX 3
void test3_4_main()
{
    struct student s[S_MAX];
    int i = 0, j = 0, k = 0, max[S_MAX], min[S_MAX], ma = 0, mi = 100;
    for(; i < S_MAX; ++i)
    {
        printf("\ntest3_4::请输入第%d个学生的学号和C语言成绩: ", i + 1);
        scanf("%d %d", &s[i].no, &s[i].c_score);
        if(s[i].c_score > ma)
        {
            j = 0;
            max[j] = s[i].no;
            ma = s[i].c_score;
        }
        else if(s[i].c_score == ma)
        {
            max[++j] = s[i].no;
        }
        if(s[i].c_score < mi)
        {
            k = 0;
            min[k] = s[i].no;
            mi = s[i].c_score;
        }
        else if(s[i].c_score == mi)
        {
            min[++k] = s[i].no;
        }
    }
    printf("\ntest3_4::max:%d, no:", ma);
    for(i = 0; i <= j; ++i)
    {
        printf(" %d", max[i]);
    }
    printf("\ntest3_4::min:%d, no:", mi);
    for(i = 0; i <= k; ++i)
    {
        printf(" %d", min[i]);
    }
}

int main()
{
    test3_1_main();
    test3_2_main();
    test3_3_main();
    test3_4_main();
    printf("\nHello world!\n");
    return 0;
}