exercism-solutions/cpp/robot-name/robot_name.cpp

62 lines
1.1 KiB
C++

#include "robot_name.h"
#include <algorithm>
#include <set>
namespace robot_name {
using namespace std;
namespace {
const size_t alpha_part_size = 2;
const size_t digit_part_size = 3;
string random_string(size_t size, char from_char, char to_char)
{
auto random_char = [from_char, to_char]() -> char {
return from_char + rand() % (to_char - from_char + 1);
};
string result(size, 0);
generate_n(result.begin(), size, random_char);
return result;
};
}
robot::robot()
{
reset();
}
void robot::reset()
{
static set<name_t> used_names;
static const size_t name_capacity = pow('Z' - 'A' + 1, alpha_part_size)
* pow('9' - '0' + 1, digit_part_size);
string new_name;
do {
new_name = random_string(alpha_part_size, 'A', 'Z')
+ random_string(digit_part_size, '0', '9');
} while (used_names.size() < name_capacity && used_names.count(new_name));
used_names.erase(name_);
name_ = new_name;
used_names.insert(name_);
}
const name_t &robot::name() const
{
return name_;
}
}