Longest Consecutive Sequences

試著使用 Tcl 解 Longest Consecutive Sequences 問題。

#!/usr/bin/env tclsh
#
# You are given an unsorted array of integers.
# Write a script to find the longest consecutive sequence.
# Print 0 if none sequence found.
#

if {$argc <= 1} {
    puts "Please input a list."
    exit
}

# To compare two list's length
proc mysortproc {x y} {
    set len1 [llength $x]
    set len2 [llength $y]

    if {$len1 > $len2} {
        return -1
    } elseif {$len1 < $len2} {
        return 1
    } else {
        return 0
    }
}

set len [llength $argv]
set mylist [lsort -integer $argv]
set last [lindex $mylist 0]
set index 0
set results [list]
lset results $index [list $last]
for {set count 1} {$count < $len} {incr count} {
    set current [lindex $mylist $count]

    if {$current != [expr $last + 1]} {
       incr index
    }

    set indexlist [lindex $results $index]
    set indexlist [lappend indexlist $current]
    lset results $index $indexlist

    set last $current
}

# Sort our results by using sublists's length
set results [lsort -command mysortproc $results]
if {[llength [lindex $results 0]] > 1} {
    puts [lindex $results 0]
} else {
    puts 0
}

如果要使用 anonymous function，則可以改寫如下：

#!/usr/bin/env tclsh
#
# You are given an unsorted array of integers.
# Write a script to find the longest consecutive sequence.
# Print 0 if none sequence found.
#

if {$argc <= 1} {
    puts "Please input a list."
    exit
}

set len [llength $argv]
set mylist [lsort -integer $argv]
set last [lindex $mylist 0]
set index 0
set results [list]
lset results $index [list $last]
for {set count 1} {$count < $len} {incr count} {
    set current [lindex $mylist $count]

    if {$current != [expr $last + 1]} {
       incr index
    }

    set indexlist [lindex $results $index]
    set indexlist [lappend indexlist $current]
    lset results $index $indexlist

    set last $current
}

# Sort our results by using sublists's length
set results [lsort -command {apply {{x y} {
    set len1 [llength $x]
    set len2 [llength $y]

    if {$len1 > $len2} {
        return -1
    } elseif {$len1 < $len2} {
        return 1
    } else {
        return 0
    }
}}} $results]
if {[llength [lindex $results 0]] > 1} {
    puts [lindex $results 0]
} else {
    puts 0
}

也可以使用其它的方式，直接記錄 Longest Consecutive Sequences 的排序，如下所示：

#!/usr/bin/env tclsh
#
# You are given an unsorted array of integers.
# Write a script to find the longest consecutive sequence.
# Print 0 if none sequence found.
#

if {$argc <= 1} {
    puts "Please input a list."
    exit
}

set len [llength $argv]
set mylist [lsort -integer $argv]
set last [lindex $mylist 0]
set index 0
set curresult [list $last]
set maxresult [list $last]
set curval 1
set maxval 1
for {set count 1} {$count < $len} {incr count} {
    set current [lindex $mylist $count]

    if {$current == [expr $last + 1]} {
       lappend curresult $current
       incr curval

       if {$curval > $maxval} {
           set maxresult $curresult
           set maxval $curval
       }
    } else {
       set curval 1
       set curresult [list $current]
    }

    set last $current
}

if {$maxval > 1} {
    puts $maxresult
} else {
    puts "0"
}