如何在linq列表中计算条件连续值
本文关键字:计算 条件 连续 列表 linq | 更新日期: 2023-09-27 17:49:34
我的列表是这样的:
var query = Enumerable.Range(0, 1440).Select((n, index) =>
{
if ((index >= 480 && index <= 749) || (index >= 810 && index <= 999) || (index >= 1080 && index <= 1299))
return 0;
else if (index >= 750 && index <= 809)
return 1;
else
return 2;
});
那么,我能找到多少索引连续有"0"值,哪些是它们的索引-即使中断"1"(不是2)- ?例如,
query[480]=query[481]=query[482]....query[749] = 0,
query[750]=query[751]...query[809] = 1,
query[810]=query[811]....query[999] = 0,
query[1000]?query[1001]...query[1079] = 2,
query[1080]=query[1081]....query[1299] = 0, etc..
所以,答案是270(1之前)+ 190(1之后)= 460虽然1080到1299之间的索引值为0,但不应该考虑它们,因为之前的值为"2"。
如何找到它们的和和索引?
LINQ版本:
int groupCount = 0;
var result = query
.Select((x, i) => new { Value = x, Index = i })
.SkipWhile(x => x.Value != 0) // Skip until first 0 is reached
.TakeWhile(x => x.Value == 0 || x.Value == 1) // Take a continuous series of 0 and 1
.Where(x => x.Value == 0) // Filter out the 1s
.GroupBy(x =>
// Treat as a new group if it's:
// 1) the 1st element, or
// 2) doesn't equal to previous number
x.Index == 0 || x.Value != query.ElementAt(x.Index - 1)
? ++groupCount
: groupCount)
.Select(x => new
{
Count = x.Count(),
Start = x.First().Index,
End = x.Last().Index
});
结果:<>之前{Count = 270, Start = 480, End = 749}{Count = 190, Start = 810, End = 999}