string s;

getline(cin,s);

采用这种输入方式可以输入空格

#include<bits/stdc++.h>
using namespace std;

int main(){

    string s;
    int zimu=0,shuzi=0,kongge=0,qita=0;
    getline(cin,s);
    for(int i=0;i<s.size();i++)
    {
        if(s[i]>='a'&&s[i]<='z')
        {
            zimu++;
        }
        else if(s[i]>='0'&&s[i]<='9')
        {
            shuzi++;
        }
        else if(s[i]==' ')
        {
            kongge++;
        }
        else qita++;
    }
    cout<<zimu<<" "<<shuzi<<" "<<kongge<<" "<<qita<<endl;
	return 0;
}