C :

#include<stdio.h>
#include<ctype.h>
int main()
{
    char a[1000];
    int i=-1;
    int zm,kg,sz,others;
    zm=kg=sz=others=0;
    gets(a);
    while(a[++i]!='\0')
    {
        if(isalpha(a[i])) zm++;
        else if(isdigit(a[i])) sz++;
        else if(isblank(a[i])) kg++;
        else others++;
    }
    printf("%d %d %d %d\n",zm,sz,kg,others);
    return 0;
}

C++ :

#include<stdio.h>
int main()
{
    int a,b,c,d,e;
    char k[100],*p;
    a=b=c=d=e=0;
    gets(k);
    p=k;
    while(*p)
    {
        if(*p>='a'&&*p<='z'||*p>='A'&&*p<='Z')
            a++;
        else if(*p==' ')
            b++;
        else if(*p>='0'&&*p<='9')
            c++;
        else d++;
        p++;
    }
    printf("%d %d %d %d\n",a,c,b,d);
    return 0;
}