A string coding algorithm for extracting compression

A few days ago, there was a little friend of C who was talking to me about a problem, which he said:

Pass in a string with the following format requirements:

Ep:a2d3b4c1d2

Then the result of extracting this string should be: AADDDBBBBCDD

The rule is, must be satisfied, the first character of the string is a letter, can be uppercase or lowercase, the second is a number, the range is 1-9, the length of the decompression must not exceed 1000 characters.

According to his request, I thought about it, implemented the algorithm, the algorithm is as follows:

#include <stdio.h> #include <stdlib.h> #include <string.h>int main (void) {//char *str = "a3b4c2d1";// Char *str = "a6b9c6d3"; char *str = "A9B9C9D9E9F9G9";  string to be decompressed int str_lenght = 0; int  i;static int count; char *p = Null;char ch;p = malloc (+) while (*str++! = ') The judging string has no pseudo 0 to the last character, and if it does, exit the loop {str_lenght = Atoi (str);//Convert the number in the string to an integer and return to the variable str_lenght  //Why do you do this step? Because I think about *str++//, the position of the pointer is pointing to the second character, minus one is to point to the first character str--;//apply 1000 bytes of memory space for the extracted characters, but this place is not good enough// If the string is not so big then there is no need to engage in such a large space, the optimization can be used in dynamic allocation, how much when the allocation of how much. while (count < 1000) {//This step is the first number in the string that will be fetched, it also represents the number of characters in the string//and then assigns a value to the allocated memory space for (i = 0; i < str_lenght; i++) {P[count] =  *str;//This count corresponds to the coordinates of the array, which is defined as the static type so that count can remember the current position//so that the next time the data is stored back from the current position of +1 (count++);} Do this step to let the pointer address offset +2, this time will be offset to the next character position to Str+=2;break;}} printf ("%s\n", p);//print the extracted data free (p);//release memory return 0;}

Operation Result:

A string coding algorithm for extracting compression