How Can I Efficiently Shuffle a std::vector in C ?

Efficient Shuffling of a std::vector

When shuffling a std::vector, efficiency plays a crucial role. The provided method using an intermediate array and type-specific knowledge is not optimal.

Modern C Approach

In C 11 and later, a more efficient approach is available:

#include <algorithm>
#include <random>

auto rng = std::default_random_engine {};
std::shuffle(std::begin(cards_), std::end(cards_), rng);

This method utilizes the std::shuffle function, which efficiently randomizes the elements. Remember to reuse the rng instance across multiple std::shuffle calls for consistent randomization.

Personalized Shuffling

If you desire distinct randomized sequences across program executions, seed the random engine with the output of std::random_device:

auto rd = std::random_device {};
auto rng = std::default_random_engine { rd() };
std::shuffle(std::begin(cards_), std::end(cards_), rng);

C 98 Approach

For C 98, the std::random_shuffle function remains applicable:

#include <algorithm>

std::random_shuffle(cards_.begin(), cards_.end());

The above is the detailed content of How Can I Efficiently Shuffle a std::vector in C ?. For more information, please follow other related articles on the PHP Chinese website!