RLE压缩和解压算法以及链表翻转

#include <stdio.h>

#include <stdlib.h>

struct RleNode

{

int count;

char ch;

struct RleNode * next;

};

//压缩字符串

struct RleNode* encode(char *str)

{

char *ptr = str;

int num = 1;

int i = 0;

struct RleNode* head, *p, *q;

head = (struct RleNode*)malloc(sizeof(struct RleNode));

head->next = NULL;

p = head;

while(*ptr != '\0')

{

char ch = *ptr;

char ch2 = ptr[i];

char ch3 = ptr[i + 1];

if(ptr[i] == ptr[i + 1])

{

num++;

}

if((ptr[i] != ptr[i + 1]) )

{

q = (struct RleNode*)malloc(sizeof(struct RleNode));

q->count = num;

q->ch = ptr[i];

q->next = NULL;

p->next = q;

p = q;

num = 1;

}

ptr++;

}

return head;

}

//解压字符串

char *decode(struct RleNode* head)

{

char *str = calloc(1,100);

int num = 0;

int i = 0;

struct RleNode* p= head->next;

if(p == NULL)

{

printf("空表");

}

else

{

while(p->next != NULL)

{

num = p->count;

while(num > 0)

{

str[i] = p->ch;

i++;

num--;

}

p = p->next;

}

num = p->count;

while(num > 0)

{

str[i++] = p->ch;

num--;

}

}

return str;

}

//链表反转

struct RleNode* reverse(struct RleNode* head)

{

struct RleNode *prev = NULL, *current = NULL, *p = head->next;

if(p == NULL)

{

printf("空表");

}

while(p != NULL)

{

prev = current;

current = p;

p = p->next;

current->next = prev;

}

head->next = current;

return head;

}

//显示链表

void disp(struct RleNode* head)

{

struct RleNode* p= head->next;

if(p == NULL)

{

printf("空链表");

}

else

{

while(p->next != NULL)

{

printf("%d%c", p->count, p->ch);

p = p->next;

}

printf("%d%c\n", p->count, p->ch);

}

}

int main()

{

struct RleNode* head = (struct RleNode*)malloc(sizeof(struct RleNode));

char *str = "aaaaahhhhhhmmmmmmmuiiiiiiiaaaaaa";

printf("源字符串：%s\n",str);

head = encode(str);

printf("压缩后为：");

disp(head);

head = reverse(head);

printf("反转后：");

disp(head);

printf("解压后为：%s",decode(head));

return 0;

}