C++代码string库函数，输入空格终止问题，采用getline

解题思路:

https://www.cnblogs.com/Alan-kx/p/14320284.html

读取空格终止导致for循环无法遍历全字符串问题

注意事项:

暂时不明
参考代码:

#include<iostream>

#include<string>

using namespace std;

void cnt_num(string);

int main()

{

    string str1;

    getline(cin,str1);

    cnt_num(str1);

    return 0;

}

void cnt_num(string str1)

{

    int num_letter=0,num_num=0,num_space=0,num_other=0;

    for(int i = 0;i<str1.size();i++)

    {

        if ((str1[i]>='a' and str1[i]<='z') or (str1[i]>='A' and str1[i]<='Z')) num_letter++;

        else if (str1[i]>='0' and str1[i]<='9') num_num++;

        else if (str1[i]==' ') num_space++;

        else num_other++;

    }

    cout<<num_letter<<' '<<num_num<<' '<<num_space<<' '<<num_other<<endl;

}