#include "stdio.h"
#include "stdlib.h"
 
//查找字符串中第一個(gè)只出現(xiàn)一次的字符
char firstSingle(char * str);
 
int main(void)
{
  char str[] = "abaccdeff";
  char tmp = firstSingle(str);
  printf("%c\n",tmp);
 
  return 0;
}
 
char firstSingle(char * str)
{
  //ASCII表有255個(gè)字符，創(chuàng)建一個(gè)255個(gè)元素的映射數(shù)組初始為0
  int asc[255] = {0};
  int i;
   
  //遍歷字符串，同時(shí)做字符的ASCII值映射到數(shù)組下標(biāo)統(tǒng)計(jì)出現(xiàn)次數(shù)；
  for(i=0;str[i]!='\0';i++)
    asc[str[i]]++;
 
  //再次遍歷，找到第一個(gè)出現(xiàn)一次的字符即為所求
  for(i=0;str[i]!='\0';i++)
    if(asc[str[i]] == 1)
      return str[i];
  //否則返回空
  return '\0';
}

#include "stdio.h"
#include "stdlib.h"
 
int continumax(char * outputstr,char * inputstr);
 
int main(void)
{
  char *in = "abcd12345ed125dd123456789";
  char *out = (char *)malloc(sizeof(char)*100);
   
  int i = continumax(out,in);
 
  printf("%d\n",i);
  printf("%s\n",out);
  return 0;
}
 
int continumax(char * outputstr, char * inputstr)
{
  int len,max,i;
  char *p;
 
  len = max = 0;
 
  //若寫成while(inputstr != '\0'),當(dāng)字符串結(jié)尾出現(xiàn)最長數(shù)字串則無法處理
  while(1)
  {  
    if(*inputstr >= '0' && *inputstr <= '9')
    {
      len++;
    }
    else
    {
      if(len >max)
      {
        max = len;
        p = inputstr - len;
      }
      len = 0;
    }
    if(*inputstr++ == 0) 
      break;
  }
 
  for(i = 0;i<max;i++)
    *outputstr++ = *p ++;
 
  *outputstr = '\0';
 
  return max;
}