为引擎。
template<class Gen>
void seed(Gen& gen)
void seed(unsigned long x0 = default_seed);
参数
Gen
种子生成器的类型。gen
种子生成器。x0
种子值。
备注
前置条件: 0 < x0
第一个种子函数生成从 gen 的后续调用返回的类型 unsigned long 的值 N 值然后扭转发生的大整数值。每个值是 gen() % 2W。
第二个种子功能将最旧的历史值 h[0] 到 x0 mod 2W，然后迭代设置每个连续的历史值 h[i] 到 (i + 1812433253 * (h[i - 1] >;AMP_gt; (W - 2))) mod 2W，范围从 1 的 i 到 N - 1。
示例
// std_tr1__random__mersenne_twister_seed.cpp
// compile with: /EHsc
#include <random>
#include <iostream>
typedef std::minstd_rand Myeng;
typedef std::mersenne_twister<unsigned int, 32, 624,
397, 31, 0x9908b0df, 11, 7, 0x9d2c5680,
15, 0xefc60000, 18> Myceng; // same as mt19937
int main()
{
Myeng eng;
Myceng ceng;
Myceng::result_type compval = ceng();
compval = compval; // to quiet "unused" warnings
std::cout << "W == " << Myceng::word_size << std::endl;
std::cout << "N == " << Myceng::state_size << std::endl;
std::cout << "M == " << Myceng::shift_size << std::endl;
std::cout << "R == " << Myceng::mask_bits << std::endl;
std::cout << "A == " << Myceng::parameter_a << std::endl;
std::cout << "U == " << Myceng::output_u << std::endl;
std::cout << "S == " << Myceng::output_s << std::endl;
std::cout << "B == " << Myceng::output_b << std::endl;
std::cout << "T == " << Myceng::output_t << std::endl;
std::cout << "C == " << Myceng::output_c << std::endl;
std::cout << "L == " << Myceng::output_l << std::endl;
std::cout << "min == " << ceng.min() << std::endl;
std::cout << "max == " << ceng.max() << std::endl;
ceng.seed(); // reseed base engine
std::cout << "a random value == " << ceng() << std::endl;
std::cout << "a random value == " << ceng() << std::endl;
std::cout << "a random value == " << ceng() << std::endl;
Myceng ceng2(eng); // construct with generator
ceng2.seed(eng); // seed with generator
Myceng ceng3(5UL); // construct with unsigned long seed
ceng3.seed(5UL); // seed with unsigned long
return (0);
}
要求
标头: <random>
命名空间: std