C++ :

#include<iostream>
#include<cstdio>
using namespace std;
int main()
{
	char c;
	int letter=0,digit=0,space=0,other=0;
	while ((c=getchar()) != '\n')
		if (isalpha(c)) letter++;
		else if (isalnum(c)) digit++;
		else if (c==' ') space++;
		else other++;
	cout<<letter<<" "<<digit<<" "<<space<<" "<<other<<endl;
	return 0;
}