C++ day1

#include <iostream>

using namespace std;

int main()
{
    string str;
   cout << "please enter input str:" << endl;
   getline(cin,str);

   cout << "str = " << str << endl;
   int len =str.size();
   int num1 = 0;
   int num2 = 0;
   int num3 = 0;
   int num4 = 0;
   int num5 = 0;
   for(int i=0; i<len;i++)
   {
     if(str[i] >='a' && str[i] <= 'z')
     {
         num1++;
     }
     else if(str[i] >= '0' && str[i] <= '9')
     {
         num2++;
     }
     else if(str[i] >= 'A' && str[i] <= 'Z')
     {
         num3++;
     }
     else if(str[i] == ' ')
     {
         num4++;
     }
     else {
         num5++;
     }
   }

   cout << "小写字符个数:"<< num1 << endl;

   cout << "数字个数:"<< num2 << endl;
   cout << "大写字符个数:"<< num3 << endl;
   cout << "空格个数:"<< num4 << endl;
   cout << "其他字符个数:"<< num5 << endl;
    return 0;
}