Anonymous user
External sort: Difference between revisions
→{{header|Nim}}
m (→{{header|Wren}}: Removed some blank lines.) |
|||
Line 923:
sort!(arr)
</lang>
=={{header|Nim}}==
{{trans|Phix}}
<lang Nim>import algorithm, heapqueue, os, random, sequtils, strformat, strutils
proc sortFiles(filenames: seq[string]) =
for filename in filenames:
var lines = filename.readFile()
lines.stripLineEnd() # Ignore last line feed, if any.
var sortedLines = sorted(lines.splitLines())
echo &"""{filename} => {sortedLines.join(", ")}"""
filename.writeFile(sortedLines.join("\n"))
proc mergeFiles(outfile: File; filenames: seq[string]) =
var queue: HeapQueue[(string, File)]
for filename in filenames:
let f = open(fileName)
queue.push (f.readLine(), f)
while queue.len > 0:
let (s, infile) = queue.pop()
outfile.write s & '\n'
if infile.endOfFile:
infile.close()
else:
queue.push((infile.readLine(), infile))
when isMainModule:
const WriteToFile = false # Compile time switch.
randomize()
let nf = rand(2..4) # Number of files.
let lp = 3 # Lines per file.
var filenames: seq[string]
var lines = toSeq(1..nf*lp)
lines.shuffle()
for i in 1..nf:
let filename = &"file{i}.txt"
filenames.add filename
let f = open(filename, fmWrite)
for l in 1..lp:
f.write &"Line {lines[^l]:2}\n"
lines.setLen(lines.len - lp)
f.close()
echo &"sorting {nf * lp} lines split over {nf} files"
sortFiles(filenames)
when WriteToFile:
let f = open("results.txt", fmWrite)
mergeFiles(f, filenames)
f.close()
else:
mergeFiles(stdout, filenames)
for filename in filenames:
removeFile(filename)</lang>
{{out}}
<pre>sorting 12 lines split over 4 files
file1.txt => Line 3, Line 4, Line 10
file2.txt => Line 1, Line 6, Line 12
file3.txt => Line 2, Line 5, Line 8
file4.txt => Line 7, Line 9, Line 11
Line 1
Line 2
Line 3
Line 4
Line 5
Line 6
Line 7
Line 8
Line 9
Line 10
Line 11
Line 12</pre>
=={{header|Perl}}==
| |||