blob: 695ccac05be79182392a02a5e039980065b42107 (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
|
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
namespace aoc2019
{
internal class Day4 : Day
{
int start, end;
public Day4()
{
var range = File.ReadLines("input/day4.in")
.First()
.Split('-')
.Select(i => int.Parse(i))
.ToList();
start = range[0]; end = range[1];
}
private bool IsValid(int i)
{
int prev = 0; bool hasDup = false;
foreach (var c in i.ToString())
{
int curr = c - '0';
if (curr < prev) return false;
if (curr == prev) hasDup = true;
prev = curr;
}
return i >= start && i <= end && hasDup;
}
public override void Part1()
{
Console.WriteLine(Enumerable.Range(start, end).Count(i => IsValid(i)));
}
private bool HasOnePair(int i)
{
var s = i.ToString();
return s.Select(c => s.Count(j => j == c)).Any(c => c == 2);
}
public override void Part2()
{
Console.WriteLine(Enumerable.Range(start,end).Count(i => IsValid(i) && HasOnePair(i)));
}
}
}
|