整数序列压缩算法,实现了variable bytes codes,参考这里http://en.wikipedia.org/wiki/Variable-width_encoding

variable_bytes_codes.c

#include<stdio.h>
#include<stdlib.h>


struct element {
  struct element *next;
  unsigned char val;
};

struct element ot = {NULL,NULL};

char stack[100] = {0};
int p = 0;

void push(char c)
{
  stack[p++] = c;
}

char pop()
{
  return stack[--p];
}


void encode(int n[], int len)
{
  int i,k ;
  struct element *cur;
  
  cur = &ot;

  for(i = 0; i < len; i++) {
    k = n[i];
    
    while(k >= 128) {
      push(k % 128);
      k = k / 128;
    }
    push(k);
    
    
    while(p > 1) {
       cur->next = malloc(sizeof(struct element));
       cur = cur->next;
       cur->val = pop();
    }

    cur->next = malloc(sizeof(struct element));
    cur = cur->next;
    cur->val = pop() + 128;
      
  }

  return;
}


void print_bytes(struct element *s)
{
  while(s != NULL) {
      printf("%d,",s->val);
    s = s->next;
  }

  printf("\n");

  return ;
}

void decode(struct element *s)
{
  int e = 0;

  while(s != NULL) {    
    
    if(s->val < 128)
      e = 128 * e + s->val; 
    else {
      e = 128 * e + (s->val - 128);
      printf("%d,",e);
      e = 0;
    }
    
    s = s->next;
  }
  printf("\n");

  return;
}


int main() 
{
  int a[5] = {257,130, 16394,5,10};
  
  
  encode(a,5);
  printf("加密后:\n");
  print_bytes(&ot);

  printf("原文:\n");
  decode(&ot);

  return 0;
}