ポインタのソート

明解Ｃ言語入門編 > 12. 構造体 >

Ruby

NINSU = 5

def compare_height(x, y)
    return  1 if (x["height"] > y["height"])
    return -1 if (x["height"] < y["height"])
    return 0
end

def compare_weight(x, y)
    return  1 if (x["weight"] > y["weight"])
    return -1 if (x["weight"] < y["weight"])
    return 0
end

def sort(data, ptr, n, compare)
    k = n - 1
    while (k >= 0)
        j = -1
        for i in 1..k
            if (compare.call(data[ptr[i-1]], data[ptr[i]]) > 0)
                j = i - 1
                ptr[i], ptr[j] = ptr[j], ptr[i]
            end
        end
        k = j
    end
end

data = []
data.push({"name" => "Sato",   "height" => 178, "weight" => 61.0})
data.push({"name" => "Sanaka", "height" => 175, "weight" => 60.5})
data.push({"name" => "Takao",  "height" => 173, "weight" => 80.0})
data.push({"name" => "Mike",   "height" => 165, "weight" => 72.0})
data.push({"name" => "Masaki", "height" => 179, "weight" => 77.5})

ptr = [0, 1, 2, 3, 4]

puts "ソ\ート前："
data.each_with_index do |d, i|
    printf("%2d:%-8s%4d%6.1f\n", i + 1, d["name"], d["height"], d["weight"])
end
puts ""

sort(data, ptr, NINSU, method(:compare_height))

puts "身長でソ\ート後："
ptr.each_with_index do |p, i|
    printf("%2d:%-8s%4d%6.1f\n", i + 1, data[p]["name"], data[p]["height"], data[p]["weight"])
end
puts ""

sort(data, ptr, NINSU, method(:compare_weight))

puts "体重でソ\ート後："
ptr.each_with_index do |p, i|
    printf("%2d:%-8s%4d%6.1f\n", i + 1, data[p]["name"], data[p]["height"], data[p]["weight"])
end
puts ""

puts "元の配列："
i = 1
data.map { |d| printf("%2d:%-8s%4d%6.1f\n", i, d["name"], d["height"], d["weight"]); i += 1 }

実行結果

L:\>ruby l:\lesson_12_100.rb
ソート前：
1:Sato 178 61.0
2:Sanaka 175 60.5
3:Takao 173 80.0
4:Mike 165 72.0
5:Masaki 179 77.5

身長でソート後：
1:Mike 165 72.0
2:Takao 173 80.0
3:Sanaka 175 60.5
4:Sato 178 61.0
5:Masaki 179 77.5

体重でソート後：
1:Sanaka 175 60.5
2:Sato 178 61.0
3:Mike 165 72.0
4:Masaki 179 77.5
5:Takao 173 80.0

元の配列：
1:Sato 178 61.0
2:Sanaka 175 60.5
3:Takao 173 80.0
4:Mike 165 72.0
5:Masaki 179 77.5