diff options
author | Iain Buclaw <ibuclaw@gdcproject.org> | 2025-01-09 23:56:49 +0100 |
---|---|---|
committer | Iain Buclaw <ibuclaw@gdcproject.org> | 2025-01-12 23:18:25 +0100 |
commit | a2e540bf0150b1a2f05924ce6d5210dc0048471d (patch) | |
tree | b46d2d634704cfea7200180a0d03ddc5303aab0b /libphobos/src/std/algorithm | |
parent | f4fa0b7d493a4ba217d989d3df75bbe3730874fc (diff) | |
download | gcc-a2e540bf0150b1a2f05924ce6d5210dc0048471d.zip gcc-a2e540bf0150b1a2f05924ce6d5210dc0048471d.tar.gz gcc-a2e540bf0150b1a2f05924ce6d5210dc0048471d.tar.bz2 |
d: Merge dmd, druntime c7902293d7, phobos 03aeafd20
D front-end changes:
- Import dmd v2.110.0-rc.1.
- An error is now given for subtracting pointers of different
types.
D runtime changes:
- Import druntime v2.110.0-rc.1.
Phobos changes:
- Import phobos v2.110.0-rc.1.
gcc/d/ChangeLog:
* dmd/MERGE: Merge upstream dmd c7902293d7.
* dmd/VERSION: Bump version to v2.110.0-rc.1.
libphobos/ChangeLog:
* libdruntime/MERGE: Merge upstream druntime c7902293d7.
* libdruntime/Makefile.am (DRUNTIME_DSOURCES): Rename
core/thread/fiber.d to core/thread/fiber/package.d. Add
core/thread/fiber/base.d.
* libdruntime/Makefile.in: Regenerate.
* src/MERGE: Merge upstream phobos 63fdb282f.
gcc/testsuite/ChangeLog:
* gdc.dg/asm3.d: Adjust test.
* gdc.dg/torture/pr96435.d: Adjust test.
Diffstat (limited to 'libphobos/src/std/algorithm')
-rw-r--r-- | libphobos/src/std/algorithm/searching.d | 131 |
1 files changed, 129 insertions, 2 deletions
diff --git a/libphobos/src/std/algorithm/searching.d b/libphobos/src/std/algorithm/searching.d index e0d2435..924ea1c 100644 --- a/libphobos/src/std/algorithm/searching.d +++ b/libphobos/src/std/algorithm/searching.d @@ -34,6 +34,7 @@ $(T2 commonPrefix, `commonPrefix("parakeet", "parachute")` returns `"para"`.) $(T2 endsWith, `endsWith("rocks", "ks")` returns `true`.) +$(T2 extrema, `extrema([2, 1, 3, 5, 4])` returns `[1, 5]`.) $(T2 find, `find("hello world", "or")` returns `"orld"` using linear search. (For binary search refer to $(REF SortedRange, std,range).)) @@ -3684,7 +3685,7 @@ Note: See_Also: - $(LREF maxElement), $(REF min, std,algorithm,comparison), $(LREF minCount), + $(LREF extrema), $(LREF maxElement), $(REF min, std,algorithm,comparison), $(LREF minCount), $(LREF minIndex), $(LREF minPos) */ auto minElement(alias map = (a => a), Range)(Range r) @@ -3865,7 +3866,7 @@ Note: See_Also: - $(LREF minElement), $(REF max, std,algorithm,comparison), $(LREF maxCount), + $(LREF extrema), $(LREF minElement), $(REF max, std,algorithm,comparison), $(LREF maxCount), $(LREF maxIndex), $(LREF maxPos) */ auto maxElement(alias map = (a => a), Range)(Range r) @@ -4035,6 +4036,132 @@ if (isInputRange!Range && !isInfinite!Range && assert(maxElement(arr) == S(145)); } +/** Returns an array of the minimum and maximum element in `r`. + * Performs `< 3n/2` comparisons, unlike the naive `< 2n`. + * Params: + * r = The range to traverse. + */ +// TODO alias map = a => a +ElementType!Range[2] extrema(Range)(Range r) +if (isInputRange!Range && !isInfinite!Range) +in (!r.empty) +{ + static if (isRandomAccessRange!Range && hasLength!Range) + { + if (r.length == 1) + return [r[0], r[0]]; + + typeof(return) result; + size_t i; + if (r.length & 1) // odd + { + result = [r[0], r[0]]; + i = 1; + } + else + { + result = (r[0] < r[1]) ? [r[0], r[1]] : [r[1], r[0]]; + i = 2; + } + // iterate pairs + const imax = r.length; + for (; i != imax; i += 2) + { + // save work + if (r[i] < r[i+1]) + { + if (r[i] < result[0]) + result[0] = r[i]; + if (r[i+1] > result[1]) + result[1] = r[i+1]; + } + else + { + if (r[i+1] < result[0]) + result[0] = r[i+1]; + if (r[i] > result[1]) + result[1] = r[i]; + } + } + return result; + } + else + { + auto first = r.front; + r.popFront; + if (r.empty) + return [first, first]; + + typeof(return) result = (first < r.front) ? [first, r.front] : [r.front, first]; + // iterate pairs + while (true) + { + r.popFront; + if (r.empty) + return result; + first = r.front; + r.popFront; + if (r.empty) + { + if (first < result[0]) + result[0] = first; + else if (first > result[1]) + result[1] = first; + return result; + } + // save work + if (first < r.front) + { + if (first < result[0]) + result[0] = first; + if (r.front > result[1]) + result[1] = r.front; + } + else + { + if (r.front < result[0]) + result[0] = r.front; + if (first > result[1]) + result[1] = first; + } + } + } +} + +/// +@safe unittest +{ + assert(extrema([5,2,9,4,1]) == [1, 9]); +} + +@safe unittest +{ + assert(extrema([8,3,7,4,9]) == [3, 9]); + assert(extrema([1,5,3,2]) == [1, 5]); + assert(extrema([2,3,3,2]) == [2, 3]); + + import std.range; + assert(iota(2, 5).extrema == [2, 4]); + assert(iota(3, 7).retro.extrema == [3, 6]); + + import std.internal.test.dummyrange; + foreach (DummyType; AllDummyRanges) + { + DummyType d; + assert(d.extrema == [1, 10]); + } + + version (StdRandomTests) + foreach (i; 0 .. 1000) + { + import std.random; + auto arr = generate!(() => uniform(0, 100)).takeExactly(uniform(1, 10)).array; + auto result = arr.extrema; + assert(result[0] == arr.minElement); + assert(result[1] == arr.maxElement); + } +} + // minPos /** Computes a subrange of `range` starting at the first occurrence of `range`'s |