OR-Tools  8.2
range_query_function.h
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1// Copyright 2010-2018 Google LLC
2// Licensed under the Apache License, Version 2.0 (the "License");
3// you may not use this file except in compliance with the License.
4// You may obtain a copy of the License at
5//
6// http://www.apache.org/licenses/LICENSE-2.0
7//
8// Unless required by applicable law or agreed to in writing, software
9// distributed under the License is distributed on an "AS IS" BASIS,
10// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
11// See the License for the specific language governing permissions and
12// limitations under the License.
13
14// The header defines an interface for functions taking and returning an int64
15// and supporting range queries over their domain and codomain.
16
17#ifndef OR_TOOLS_UTIL_RANGE_QUERY_FUNCTION_H_
18#define OR_TOOLS_UTIL_RANGE_QUERY_FUNCTION_H_
19
20#include <functional>
21#include <memory>
22
24
25namespace operations_research {
26// RangeIntToIntFunction is an interface to int64->int64 functions supporting
27// fast answer to range queries about their domain/codomain.
29 public:
30 virtual ~RangeIntToIntFunction() = default;
31
32 // Suppose f is the abstract underlying function.
33 // Returns f(argument).
34 // TODO(user): Rename to Run
35 virtual int64 Query(int64 argument) const = 0;
36 // Returns min_x f(x), where x is in [from, to).
37 virtual int64 RangeMin(int64 from, int64 to) const = 0;
38 // Returns max_x f(x), where x is in [from, to).
39 virtual int64 RangeMax(int64 from, int64 to) const = 0;
40 // Returns the first x from [range_begin, range_end) for which f(x) is in
41 // [interval_begin, interval_end), or range_end if there is no such x.
42 virtual int64 RangeFirstInsideInterval(int64 range_begin, int64 range_end,
43 int64 interval_begin,
44 int64 interval_end) const = 0;
45 // Returns the last x from [range_begin, range_end) for which f(x) is in
46 // [interval_begin, interval_end), or range_begin-1 if there is no such x.
47 virtual int64 RangeLastInsideInterval(int64 range_begin, int64 range_end,
48 int64 interval_begin,
49 int64 interval_end) const = 0;
50};
51
52// RangeMinMaxIndexFunction is different from RangeIntToIntFunction in two ways:
53//
54// 1. It does not support codomain or value queries.
55//
56// 2. For domain queries it returns an argument where the minimum/maximum is
57// attained, rather than the minimum/maximum value.
59 public:
60 virtual ~RangeMinMaxIndexFunction() = default;
61 // Suppose f is the abstract underlying function.
62 // Returns an x from [from, to), such that f(x) => f(y) for every y from
63 // [from, to).
64 virtual int64 RangeMaxArgument(int64 from, int64 to) const = 0;
65 // Returns an x from [from, to), such that f(x) <= f(y) for every y from
66 // [from, to).
67 virtual int64 RangeMinArgument(int64 from, int64 to) const = 0;
68};
69
70// A copy of f is going to be stored in the returned object, so its closure
71// should remain intact as long as the returned object is being used.
73// It is assumed that f is defined over the interval [domain_start, domain_end).
74// The function scans f once and it is safe to destroy f and its closure after
75// MakeCachedIntToIntFunction returns.
77 const std::function<int64(int64)>& f, int64 domain_start, int64 domain_end);
78// It is safe to destroy the first argument and its closure after
79// MakeCachedRangeMinMaxIndexFunction returns.
81 const std::function<int64(int64)>& f, int64 domain_start, int64 domain_end);
82} // namespace operations_research
83
84#endif // OR_TOOLS_UTIL_RANGE_QUERY_FUNCTION_H_
virtual int64 Query(int64 argument) const =0
virtual int64 RangeFirstInsideInterval(int64 range_begin, int64 range_end, int64 interval_begin, int64 interval_end) const =0
virtual int64 RangeLastInsideInterval(int64 range_begin, int64 range_end, int64 interval_begin, int64 interval_end) const =0
virtual int64 RangeMax(int64 from, int64 to) const =0
virtual int64 RangeMin(int64 from, int64 to) const =0
virtual int64 RangeMaxArgument(int64 from, int64 to) const =0
virtual int64 RangeMinArgument(int64 from, int64 to) const =0
int64_t int64
The vehicle routing library lets one model and solve generic vehicle routing problems ranging from th...
RangeMinMaxIndexFunction * MakeCachedRangeMinMaxIndexFunction(const std::function< int64(int64)> &f, int64 domain_start, int64 domain_end)
RangeIntToIntFunction * MakeBareIntToIntFunction(std::function< int64(int64)> f)
RangeIntToIntFunction * MakeCachedIntToIntFunction(const std::function< int64(int64)> &f, int64 domain_start, int64 domain_end)