add day4

day4/day4.jl

@@ -0,0 +1,77 @@
+#!/usr/bin/env julia
+
+using Test
+
+function parse_line_ranges(line)
+  parts = split(line, ',')
+  ranges = Vector{UnitRange{Int64}}()
+  for p in parts
+    start, stop = split(p, '-', limit=2)
+    prange = UnitRange(parse(Int64, start), parse(Int64, stop))
+    push!(ranges, prange)
+  end
+  return ranges
+end
+
+function line_range_contained(line)
+  ranges = parse_line_ranges(line)
+  inter = intersect(ranges[1], ranges[2])
+  return (inter == ranges[1] || inter == ranges[2])
+end
+
+function line_range_overlap(line)
+  ranges = parse_line_ranges(line)
+  inter = intersect(ranges[1], ranges[2])
+  return length(inter) > 0
+end
+
+function count_range_contained(infile)
+  rsum = 0
+
+  open(infile, "r") do io
+    for line in eachline(io)
+      if line_range_contained(line)
+        rsum += 1
+      end
+    end
+  end
+
+  return rsum
+end
+
+function count_range_overlap(infile)
+  osum = 0
+
+  open(infile, "r") do io
+    for line in eachline(io)
+      if line_range_overlap(line)
+        osum += 1
+      end
+    end
+  end
+
+  return osum
+end
+
+function test()
+  @testset "elf cleaning contained" verbose=true begin
+    @test count_range_contained("example.txt") == 2
+    @test count_range_contained("input.txt") == 500
+  end
+  @testset "elf cleaning overlap" verbose=true begin
+    @test count_range_overlap("example.txt") == 4
+    @test count_range_overlap("input.txt") == 815
+  end
+end
+
+function main()
+  if size(ARGS, 1) == 0
+    test()
+  else
+    infile = ARGS[1]
+    println("infile = ", infile)
+    println("bad assignments: ", count_range_contained(infile))
+  end
+end
+
+main()

day4/example.txt

@@ -0,0 +1,6 @@
+2-4,6-8
+2-3,4-5
+5-7,7-9
+2-8,3-7
+6-6,4-6
+2-6,4-8