1
#include <stdio.h>
2
int main()
3
{
4
  char s[] = "Hello";
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  char * p;
6
  for(p=s;*p!=‘\0’;p++)
7
  {
8
    printf("%c", *p);
9
  }
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  return 0;
11
}

1
#include <stdio.h>
2
void Print(const char * p1, const char * p2)
3
{
4
  for(;(p2-p1)>0;p1++)
5
  {
6
    printf("%c", *p1);
7
  }
8
}
9
int main()
10
{
11
  const char * s = "Tesla123";
12
  Print(s, s+5);
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  printf("\n");
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  Print(s, s+3);
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  printf("\n");
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  return 0;
17
}

1
#include <stdio.h>
2
#include <string.h>
3
void ForEach(void *a, int width, int num, void (*f)(void *))
4
{
5
  for (int i = 0; i < num; ++i)
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  {
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    f((char*)a + width * i);
8
  }
9
}
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void PrintSquare(void *p)
11
{
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  int *q = (int*)p;
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  int n = *q;
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  printf("%d,", n * n);
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}
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void PrintChar(void *p)
17
{
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  char *q = (char*)p;
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  printf("%c,", *q);
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}
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int main()
22
{
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  int a[5] = {1, 2, 3, 4, 5};
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  char s[] = "hello!";
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  ForEach(a, sizeof(int), sizeof(a)/sizeof(int),PrintSquare);
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  printf("\n");
27
  ForEach(s, sizeof(char), strlen(s), PrintChar);
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  printf("\n");
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  return 0;
30
}

1
#include <stdio.h>
2
void Memcpy(char *src, char *dest, int n)
3
{
4
  for (int i=0;i<n;i++)
5
  {
6
    dest[i] = src[i];
7
  }
8
}
9
int Strlen(char *s)
10
{
11
  int i;
12
  for (i = 0; s[i]; ++i);
13
  return i+1;
14
}
15
int main()
16
{
17
  int a;
18
  char s1[30];
19
  char s2[30];
20
  int t;
21
  scanf("%d", &t);
22
  for (int i = 0; i < t; ++i)
23
  {
24
    scanf("%d", &a);
25
    int b = 99999999;
26
    Memcpy((char*)&a, (char*)&b, sizeof(int));
27
    printf("%d\n", b);
28
  }
29
  for (int i = 0; i < t; ++i)
30
  {
31
    scanf("%s", s1);
32
    Memcpy(s1, s2, Strlen(s1));
33
    printf("%s\n", s2);
34
  }
35
  return 0;
36
}

1
#include <stdio.h>
2
void Double(int * p, int n)
3
{
4
  for(int i = 0; i < n; ++i)
5
  p[i] *= 2;
6
}
7
int main()
8
{
9
  int a[3][4] = {{1, 2, 3, 4}, {5, 6, 7, 8}, {9, 10, 11, 12}};
10
  Double(a[1],8);
11
  for(int i = 0; i < 3; ++i)
12
  {
13
    for(int j = 0; j < 4; ++j)
14
      printf("%d,", a[i][j]);
15
    printf("\n");
16
  }
17
  return 0;
18
}

1
#include <stdio.h>
2
void Memcpy(void *src, void *dest, int size)
3
{
4
  char *csrc = *src;
5
  char *cdest = *dest;
6
  for (int i=0;i<size;i++)
7
  {
8
    cdest[i] = csrc[i];
9
  }
10
}
11
void Print(int *p, int size)
12
{
13
  for (int i = 0; i < size; ++i)
14
  {
15
    printf("%d", p[i]);
16
    if (i < size - 1)
17
    {
18
      printf(",");
19
    }
20
  }
21
  printf("\n");
22
}
23
int main()
24
{
25
  int a[10];
26
  int n;
27
  scanf("%d", &n);
28
  for (int i = 0; i < n; ++i)
29
  {
30
    scanf("%d", &a[i]);
31
  }
32
  int b[10] = {0};
33
  Memcpy(a, b, sizeof(a));
34
  Print(b, n);
35
  int c[10] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
36
  Memcpy(c, c + 5, 5 * sizeof(int)); // 将c的前一半拷贝到后一半
37
  Print(c, 10);
38
  char s[10] = "123456789";
39
  Memcpy(s + 2, s + 4, 5); // 将s[2]开始的5个字符拷贝到s[4]开始的地方
40
  printf("%s\n", s);
41
  char s1[10] = "123456789";
42
  Memcpy(s1 + 5, s1 + 1, 4); // 将s1[5]开始的4个字符拷贝到s1[1]开始的地方
43
  printf("%s\n", s1);
44
  return 0;
45
}

1
#include <stdio.h>
2
#include <stdlib.h>
3
/* TODO */
4
int Compare1(void * n1, void * n2)
5
{
6
  int * p1 = (int * )n1;
7
  int * p2 = (int * )n2;
8
  return ((*p1)%10) - ((*p2)%10);
9
}
10
int Compare2(void * n1, void * n2)
11
{
12
  int * p1 = (int * )n1;
13
  int * p2 = (int * )n2;
14
  return *p1 - *p2;
15
}
16
#define eps 1e-6
17
int Compare3(void * n1, void * n2)
18
{
19
  float * p1 = (float * )n1;float * p2 = (float * )n2;
20
  if( * p1 - * p2 > eps)
21
    return 1;
22
  else if(* p2 - * p1 > eps)
23
    return -1;
24
  else
25
    return 0;
26
}
27
// MyMax函数，根据比较函数找到数组中的最大元素
28
void *MyMax(void *array, size_t size,int n, int (*compare)(const void *, const void *))
29
{
30
  void *max_element = array;
31
  for (int i = 1; i < n; ++i)
32
  {
33
    if (compare((char *)array + i * size, max_element) > 0)
34
    {
35
      max_element = (char *)array + i * size;
36
    }
37
  }
38
  return max_element;
39
}
40
int main()
41
{
42
  int t;
43
  scanf("%d", &t);
44
  while (t--)
45
  {
46
    int n;
47
    scanf("%d", &n);
48
    int a[10];
49
    float d[10];
50
    for (int i = 0; i < n; ++i)
51
    {
52
      scanf("%d", &a[i]);
53
    }
54
    for (int i = 0; i < n; ++i)
55
    {
56
      scanf("%f", &d[i]);
57
    }
58
    int * p = (int *)MyMax(a, sizeof(int), n, Compare1);
59
    printf("%d\n", *p);
60
    p = (int *)MyMax(a, sizeof(int), n, Compare2);
61
    printf("%d\n", *p);
62
    float * pd = (float *)MyMax(d, sizeof(float), n, Compare3);
63
    printf("%f\n", *pd);
64
  }
65
  return 0;
66
}

1
#include <stdio.h>
2
int main()
3
{
4
  int x,y,z;
5
  x = 10;
6
  y = 20;
7
  z = 30;
8
  int * a[3] = {&x, &y, &z};
9
  for(int **p=a; p < a + 3; ++p)
10
  {
11
    printf("%d\n",*(*p));
12
  }
13
  return 0;
14
}

1
#include <stdio.h>
2
void SwapMemory(void * m1, void * m2, int size)
3
{
4
  char temp;
5
  char *cm1 = (char *)m1;
6
  char *cm2 = (char *)m2;
7
  for (int i=0;i<size;i++)
8
  {
9
    temp = cm1[i];
10
    cm1[i] = cm2[i];
11
    cm2[i] = temp;
12
  }
13
}
14
void PrintIntArray(int * a, int n)
15
{
16
  for(int i = 0;i < n; ++i)
17
  {
18
    printf("%d,", a[i]);
19
  }
20
  printf("\n");
21
}
22
int main()
23
{
24
  int a[5] = {1, 2, 3, 4, 5};int b[5] = {10, 20, 30, 40, 50};
25
  SwapMemory(a, b, 5 * sizeof(int));
26
  PrintIntArray(a, 5);
27
  PrintIntArray(b, 5);
28
  char s1[] = "12345";
29
  char s2[] = "abcde";
30
  SwapMemory(s1, s2, 5);
31
  printf("%s\n", s1);
32
  printf("%s\n", s2);
33
  return 0;
34
}