Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
651 views
in Technique[技术] by (71.8m points)

c# - Can LINQ be used to find gaps in a sorted list?

Is it possible for me to use LINQ in a way that allows me to determine that "9" is the first missing value in the sorted list without using a for-loop and comparing each value to the one adjacent to it?

var listStringVals = new [] { "7", "13", "8", "12", "10", "11", "14" };
// sort list to "7","8","10","11","12","13","14"
var sortedList = listStringVals.OrderBy(c => int.Parse(c)).ToList();
// need some magic here to get the first gap in the sorted list
See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

Let

var strings = new string[] { "7", "13", "8", "12", "10", "11", "14" };

Then

var list = Array.ConvertAll(strings, s => Int32.Parse(s)).OrderBy(i => i);
// or
var list = strings.Select(s => int.Parse(s)).OrderBy(i => i);
// or
var list = strings.OrderBy(s => int.Parse(s));

(note this question)

and then

var result = Enumerable.Range(list.Min(), list.Count).Except(list).First(); // 9
// or
int min = list.Min(), max = list.Max();
var result = Enumerable.Range(min, max - min + 1).Except(list).First();

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...