帮帮忙看一下第四题，球球了

Question

Answer 1

#include <iostream>
#include <string>
using namespace std;
int main()
{
    string s;
    int num[4] = {0};
    cout << "输入一行字符：";
    getline(cin, s);
    for (int i = 0; i < s.size() ; i++)
    {
        if ((s[i] >= 'A' && s[i] <= 'Z') || (s[i] >= 'a' && s[i] <= 'z'))
            num[0]++;
        else if (s[i] >= '0' && s[i] <= '9')
            num[1]++;
        else if (s[i] == ' ')
            num[2]++;
        else
            num[3]++;
    }
    cout << "英文字符个数是：" << num[0] << endl;
    cout << "数字字符个数是：" << num[1] << endl;
    cout << "空格字符个数是：" << num[2] << endl;
    cout << "其他字符个数是：" << num[3] << endl;
    return 0;
}