酔堀電會麻隈議JAVA糞?
扮寂:2011-04-02 Linyco
package Utils.Sort;
/**
*酔堀電會?勣箔棋電會議方怏駅倬糞?Comparable俊笥
*/
public class QuickSort implements SortStrategy
{ private static final int CUTOFF = 3; //輝圷殆方寄噐緩峙扮寡喘 酔堀電會
/**
*旋喘酔堀電會麻隈斤方怏obj序佩電會?勣箔棋電會議方怏駅倬糞?阻 Comparable俊笥
*/
public void sort(Comparable[] obj)
{ if (obj == null)
{ throw new NullPointerException("The argument can not be null!");
}
quickSort(obj, 0, obj.length - 1);
}
/**
*斤方怏obj酔堀電會
obj 棋電會議方怏
left 方怏議和順
right 方怏議貧順
*/
private void quickSort(Comparable[] obj, int left, int right)
{ if (left + CUTOFF > right)
{ SortStrategy ss = new ChooseSort();
ss.sort(obj);
} else
{ //孀竃圃已泣?旺繍万慧壓方怏恷朔中議了崔
pivot(obj, left, right);
int i = left, j = right - 1;
Comparable tmp = null;
while (true)
{ //繍i, j蛍艶卞欺寄噐/弌噐圃摘峙議了崔
//咀葎方怏議及匯倖才宜方及屈倖圷殆蛍艶弌噐才寄噐圃 摘圷?侭參音氏窟伏方怏埆順
while (obj[++i].compareTo(obj[right - 1]) < 0) {}
while (obj[--j].compareTo(obj[right - 1]) > 0) {}
//住算
if (i < j)
{ tmp = obj[i];
obj[i] = obj[j];
obj[j] = tmp;
}
else break;
}
//繍圃摘峙嚥i峺?議峙住算
tmp = obj[i];
obj[i] = obj[right - 1];
obj[right - 1] = tmp;
//斤圃摘峙恣迦才嘔迦方怏写偬序佩酔堀電會
quickSort(obj, left, i - 1);
quickSort(obj, i + 1, right); }
}
/**
*壓方怏obj嶄僉函圃摘圷?僉函圭隈葎函方怏及匯倖、嶄寂匯倖、恷朔匯倖圷殆 嶄嶄寂議匯倖。繍圃摘圷崔噐宜方及屈倖了崔?眉倖嶄恷寄議慧壓方怏恷朔匯倖了崔?恷 弌議慧壓及匯倖了崔
obj 勣僉夲圃摘圷議方怏
left 方怏議和順
right 方怏議貧順
*/
private void pivot(Comparable[] obj, int left, int right)
{ int center = (left + right) / 2;
Comparable tmp = null;
if (obj[left].compareTo(obj[center]) > 0)
{ tmp = obj[left];
obj[left] = obj[center];
obj[center] = tmp;
}
if (obj[left].compareTo(obj[right]) > 0)
{ tmp = obj[left];
obj[left] = obj[right];
obj[right] = tmp;
}
if (obj[center].compareTo(obj[right]) > 0)
{ tmp = obj[center];
obj[center] = obj[right];
obj[center] = tmp;
}
//繍圃摘圷崔噐方怏議宜方及屈倖
tmp = obj[center];
obj[center] = obj[right - 1];
obj[right - 1] = tmp;
}
}
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