HDU 1425 sort

堆排序

题目链接http://acm.hdu.edu.cn/showproblem.php?pid=1425

关于堆排序讲解详看http://www.cnblogs.com/dolphin0520/archive/2011/10/06/2199741.html

代码跑了562MS 实在是仰慕用93MS跑出来的

这个题还必须用C交 用GCC交会TLE

View Code

 1 #include <stdio.h>

 2 #include <stdlib.h>

 3 #include <string.h>

 4 #define  N 1000005

 5 int a[N];

 6 void heapadjust(int *a,int i,int n)

 7 {

 8     int lchild=2*i,rchild=2*i+1;

 9     int max=i,t;

10     if(i<=n/2)

11     {

12         if(lchild<=n&&a[lchild]>a[max])

13     {

14         max=lchild;

15     }

16     if(rchild<=n&&a[rchild]>a[max])

17     {

18         max=rchild;

19     }

20     if(max!=i)

21     {

22         t=a[i];a[i]=a[max];a[max]=t;

23         heapadjust(a,max,n);

24     }

25     }

26 }

27 void heapbuild(int *a,int n)

28 {

29     int i;

30     for(i=n/2;i>=1;i--)

31     {

32         heapadjust(a,i,n);

33     }

34 }

35 void heapsort(int *a,int n)

36 {

37     int i,t;

38     heapbuild(a,n);

39     for(i=n;i>=1;i--)

40     {

41         t=a[1];a[1]=a[i];a[i]=t;

42         heapadjust(a,1,i-1);

43     }

44 }

45 int main()

46 {

47     int i,n,m;

48     while(scanf("%d %d",&n,&m)!=EOF)

49     {

50         for( i=1;i<=n;i++)

51     {

52         scanf("%d",&a[i]);

53     }

54     heapsort(a,n);

55     for(i=n;i>n-m+1;i--)

56     {

57         printf("%d ",a[i]);

58     }

59     printf("%d",a[n-m+1]);

60     puts("");

61     }

62     return 0;

63 }