C语言字符型数组问题

68.给定某个字符数组，统计数组中所有英文字符和阿拉伯数字的个数，比如“123fdd”中有英文字符有3个，数字3个。

你好！c语言如下

#include<stdio.h>
void main(){
    char a[1000];
    int i=0;
    int n_engchar=0;//英文字符个数 
    int n_numchar=0;//阿拉伯数字个数 
    printf("请输入字符串：\n");
    scanf("%s",&a);
    while(a[i]!='\0'){
        if(a[i]<='9' && a[i]>='0' ) n_numchar+=1;
        if(a[i]<='z' && a[i]>='a' || (a[i]<='Z' && a[i]>='A')) n_engchar+=1;
        i = i +1;
    }
    printf("英文字符%d个,阿拉伯数字%d个",n_engchar,n_numchar);
} 

char *str = "abc";
int char_count =0;
int num_count = 0;
while(*str) {
  if(*str >= ’0‘ && *str <='9') {
    num_count++;
  } else if((*str>='a' && *str <='z') ||(*str>='A' && *str <='Z')){
    char_count++;
  }
  str++;
}

#include<stdio.h>
int main(void)// x=
{
  char test[]={'1','2','3','d','d','d'};
  int num_1=0;
  int num_2=0;
  int i,j,z;
  char a[52]={'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z','A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z'};
  char b[10]={'0','1','2','3','4','5','6','7','8','9'};
  for(i=0;i<sizeof(test);i++)
  {
    for(j=0;j<52;j++)
    {
      if(test[i]==a[j])
      {
        num_1++;
      }
      
    }
    for(z=0;z<10;z++)
    {
      if(test[i]==b[z])
      {
        num_2++;
      }
    }
  }
  printf("the letter: %d, the number: %d",num_1,num_2);


}

用c函数， isdigit判断是否是数字，isalpha判断是否为字母，在ctype.h文件里面，还有其他判断函数。