习题12.23
//连接字符串到动态数组
char *c = new char[20](); char a[] = "hello "; char b[] = "world"; strcopy(c, a); strcopy(c+strlen(a), b); cout<<c<<endl;
// 连接string到动态数组 char *c = new char[20](); string a = "hello "; string b = "world"; size_t idx = 0; for(const auto &v : a) c[idx++] = v; for(const auto &v : b) c[idx++] = v; cout<<v<<endl;