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robot_name: rand() -> c++11 random

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This commit is contained in:
Dmitry Kokorin 2016-03-06 19:38:58 +03:00
parent 287152896a
commit 77c36f8e10
1 changed files with 14 additions and 5 deletions
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19
cpp/robot-name/robot_name.cpp
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@ -2,6 +2,7 @@
#include <algorithm>
#include <set>
#include <random>
namespace robot_name {
@ -11,14 +12,18 @@ using namespace std;
namespace {
typedef uniform_int_distribution<char> distribution_t;
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)
string random_string(size_t size, distribution_t &distribution)
{
auto random_char = [from_char, to_char]() -> char {
return from_char + rand() % (to_char - from_char + 1);
static default_random_engine engine;
auto random_char = [&distribution]() -> char {
return distribution(engine);
};
string result(size, 0);
@ -40,12 +45,16 @@ 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);
static distribution_t alpha_distribution('A', 'Z');
static distribution_t digit_distribution('0', '9');
string new_name;
do {
new_name = random_string(alpha_part_size, 'A', 'Z')
+ random_string(digit_part_size, '0', '9');
new_name = random_string(alpha_part_size, alpha_distribution)
+ random_string(digit_part_size, digit_distribution);
} while (used_names.size() < name_capacity && used_names.count(new_name));