minigo/cc/zobrist.cc at master · sysuwyc/minigo

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// Licensed under the Apache License, Version 2.0 (the "License");

// you may not use this file except in compliance with the License.

// You may obtain a copy of the License at

// http://www.apache.org/licenses/LICENSE-2.0

// Unless required by applicable law or agreed to in writing, software

// distributed under the License is distributed on an "AS IS" BASIS,

// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

// See the License for the specific language governing permissions and

// limitations under the License.

#include "cc/zobrist.h"

#include "cc/random.h"

namespace minigo {

namespace zobrist {

namespace internal {

Hash kBlackToPlayHash;

Hash kOpponentPassedHash;

std::array<std::array<Hash, 3>, kNumMoves> kMoveHashes;

std::array<Hash, kN * kN> kKoHashes;

std::array<Hash, kN * kN> kIllegalEmptyPointHashes;

} // namespace internal

void Init(uint64_t seed) {

minigo::Random rnd(seed, Random::kUniqueStream);

internal::kBlackToPlayHash = rnd.UniformUint64();

internal::kOpponentPassedHash = rnd.UniformUint64();

for (auto& x : internal::kMoveHashes) {

for (size_t i = 0; i < x.size(); ++i) {

// For simplicity, the hashes are indexed by kMoveHashes[coord][color].

// Set the empty hash to 0 for each position.

x[i] = i == static_cast<int>(Color::kEmpty) ? 0 : rnd.UniformUint64();

}

for (auto& x : internal::kKoHashes) {

x = rnd.UniformUint64();

}

for (auto& x : internal::kIllegalEmptyPointHashes) {

x = rnd.UniformUint64();

}

} // namespace zobrist

} // namespace minigo