程序代码：

#include<iostream>
#include<string>
using namespace std;
void search(char *s,char c[]);
int main()
{
    char string[100];
    cout<<"please enter string:"<<endl;
    cin>>string;
    char *p;
    p=string;
    search(p,string);
     return 0;
}
void search(char *s,char c[])
{
    int i;
    int a=0,b=0,f=0,d=0;
    int stren=0;
    s=c;
    while(*s!='\0')
    {
        s++;
        stren++;
    }
    for(i=0;i<stren;i++)
    {
        if((c[i]>='a'&&c[i]<='z')||(c[i]>='A'&&c[i]<='Z'))
        {
            a++;
        }
        else if (c[i]>=0&&c[i]<=9)
        {
            b++;     
        }
        else if(c[i]==' ')
        {
            f++;    
        }
        else
        {
            d++;
        }
    }
    cout<<"字母的个数:"<<a<<endl;
    cout<<"数字的个数:"<<b<<endl;
    cout<<"空格的个数:"<<f<<endl;
    cout<<"其它的个数:"<<d<<endl;
    cout<<endl;
}