#include <stdio.h>
#include <string.h>
int reduce (char s[])
{
    char *scopy;
int len=strlen(s),flag=0,count=0,totalcount;
for(int i=0;i<len-1;)
        {
        if(s[i]!=s[i+1]) *scopy++=*s;
          i++;
            }
*scopy='\0';
strcpy(s,scopy);
return len-strlen(scopy);
}

void main()
{
    char ss[]={"Press***12225"};
    int r=reduce(ss);
printf("%d",r);
}

额，你这个结果是错的。。。

你好！我又这样改了一下，可是怎么还不对啊。。。麻烦指点一下。。谢谢啊
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
int reduce (char s[])
{
    int len=strlen(s);
    char *scopy;
     scopy=(char *)malloc((len+1)*sizeof(char));

while(*(s+1)!='\0')
        {
        if(*s!=*(s+1)) *scopy++=*s;
          s++;
            }
*scopy='\0';
strcpy(s,scopy);
return len-strlen(s);
}

void main()
{
    char ss[]={"Press***12225"};
    int r;
    r=reduce(ss);
printf("%d\n",r);
}