
#include <stdio.h>
#include <string.h>

class String
    {
public:
    String(const char *s)
        {
        len = strlen(s);
        str = strcpy(new char[len + 1], s);
        }
    String(const String &s)
        {
        len = s.len;
        str = strcpy(new char[len + 1], s.str);
        }
    ~String() { delete str; }
    size_t length() { return len; }
    const char *text() { return str; }
    void cat(char c)
        {
        char *p = strcpy(new char[len + 2], str);
        p[len++] = c;
        p[len] = '\0';
        delete str;
        str = p;
        }
private:
    size_t len;
    char *str;
    };

int main()
    {
    String s1("hello");
    String s2(s1);
    printf("s1 = %s\n", s1.text());
    printf("s2 = %s\n", s2.text());
    s1.cat('!');
    printf("s1 = %s\n", s1.text());
    printf("s2 = %s\n", s2.text());
    return 0;
    }
