8bb54b04ef
FYI: find ortools \( -type d -name .git -prune \) -o -type f -print0 | xargs -0 sed -i 's/\(Copyright 2010\)-2018/\1-2021/g'
51 lines
1.4 KiB
C++
51 lines
1.4 KiB
C++
// Copyright 2010-2021 Google LLC
|
|
// 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.
|
|
|
|
#ifndef OR_TOOLS_UTIL_CACHED_LOG_H_
|
|
#define OR_TOOLS_UTIL_CACHED_LOG_H_
|
|
|
|
#include <math.h>
|
|
|
|
#include <vector>
|
|
|
|
#include "ortools/base/basictypes.h"
|
|
#include "ortools/base/integral_types.h"
|
|
#include "ortools/base/logging.h"
|
|
#include "ortools/base/macros.h"
|
|
|
|
namespace operations_research {
|
|
// This class is used when manipulating search space estimations. It
|
|
// provides fast access to log of a domain size.
|
|
// Future Extensions:
|
|
// - Sum of log on an array.
|
|
// - Sum of log on an array with callback.
|
|
|
|
class CachedLog {
|
|
public:
|
|
CachedLog();
|
|
~CachedLog();
|
|
|
|
// This method can only be called once, and with a cache_size > 0.
|
|
void Init(int cache_size);
|
|
|
|
// Returns the log2 of 'input'.
|
|
double Log2(int64_t input) const;
|
|
|
|
private:
|
|
std::vector<double> cache_;
|
|
DISALLOW_COPY_AND_ASSIGN(CachedLog);
|
|
};
|
|
} // namespace operations_research
|
|
|
|
#endif // OR_TOOLS_UTIL_CACHED_LOG_H_
|