/
Quicksort.cs
80 lines (69 loc) · 1.86 KB
/
Quicksort.cs
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using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace Quicksort
{
class Quicksort
{
public static void QSort(int[] items)
{
qs(items, 0, items.Length - 1);
}
static void qs(int[] items, int left, int right)
{
int i, j;
int x;
// tは入れ替え用
int t;
i = left;
j = right;
// xは軸用。初期値は配列の中央
x = items[(left + right)/2];
do
{
while ((items[i] < x) && (i < right)) i++;
while ((x < items[j]) && (j > left)) j--;
if (i <= j)
{
t = items[i];
items[i] = items[j];
items[j] = t;
i++;
j--;
}
} while (i <= j);
if (left < j)
{
// qs()のrightの値にjを渡す
qs(items, left, j);
}
if (i < right)
{
// qs()のleftの値にiを渡す
qs(items, i, right);
}
}
}
class QSdemo
{
static void Main()
{
int[] demo = { 520, 84, 16848, 2164, 132, 684, 32, 86, 21, 87, 1, 874, 8216541, 2404 };
int i;
Console.WriteLine("元の配列は");
for (i = 0; i < demo.Length; i++)
{
Console.WriteLine(demo[i]);
}
Console.WriteLine();
Quicksort.QSort(demo);
Console.WriteLine("並び替え後の配列は");
for (i = 0; i < demo.Length; i++)
{
Console.WriteLine( demo[i]);
}
Console.WriteLine();
}
}
}