编程统计字符个数，输出大写，小写，数字，空格

以下是C++统计字符个数并输出大写、小写、数字、空格的示例代码：

#include <iostream>
#include <cstring>
using namespace std;

int main()
{
    char str[100];
    int len, i, upper = 0, lower = 0, digit = 0, space = 0, other = 0;

    cout << "请输入一个字符串：";
    cin.getline(str, 100);
    len = strlen(str);

    for (i = 0; i < len; i++)
    {
        if (str[i] >= 'A' && str[i] <= 'Z')
            upper++;
        else if (str[i] >= 'a' && str[i] <= 'z')
            lower++;
        else if (str[i] >= '0' && str[i] <= '9')
            digit++;
        else if (str[i] == ' ')
            space++;
        else
            other++;
    }

    cout << "大写字母个数：" << upper << endl;
    cout << "小写字母个数：" << lower << endl;
    cout << "数字个数：" << digit << endl;
    cout << "空格个数：" << space << endl;

    return 0;
}