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version 2.099.0

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Function std.algorithm.searching.maxElement

Iterates the passed range and returns the maximal element. A custom mapping function can be passed to map. In other languages this is sometimes called argmax.

auto maxElement(alias map, Range) (
  Range r
)
if (isInputRange!Range && !isInfinite!Range);

auto maxElement(alias map, Range, RangeElementType) (
  Range r,
  RangeElementType seed
)
if (isInputRange!Range && !isInfinite!Range && !is(CommonType!(ElementType!Range, RangeElementType) == void));

Complexity

O(n) Exactly n - 1 comparisons are needed.

Parameters

NameDescription
map custom accessor for the comparison key
r range from which the maximum element will be selected
seed custom seed to use as initial element

Precondition

If a seed is not given, r must not be empty.

Returns

The maximal element of the passed-in range.

Note

If at least one of the arguments is NaN, the result is an unspecified value. See minElement for examples on how to cope with NaNs.

See Also

minElement, max, maxCount, maxIndex, maxPos

Example

import std.range : enumerate;
import std.typecons : tuple;
writeln([2, 1, 4, 3].maxElement); // 4

// allows to get the index of an element too
writeln([2, 1, 4, 3].enumerate.maxElement!"a.value"); // tuple(2, 4)

// any custom accessor can be passed
writeln([[0, 4], [1, 2]].maxElement!"a[1]"); // [0, 4]

// can be seeded
int[] arr;
writeln(arr.minElement(1)); // 1

Authors

Andrei Alexandrescu

License

Boost License 1.0.