poj2823Sliding Window(线段树求最值）

链接

裸线段树 这题时间卡的挺棒

 1 #include <iostream>

 2 #include<cstdio>

 3 #include<cstring>

 4 #include<algorithm>

 5 #include<stdlib.h>

 6 

 7 using namespace std;

 8 #define N 1000010

 9 #define INF 0xfffffff

10 int s[N<<2],lm[N<<2],sm[N<<2];

11 int ma[N],mi[N],o;

12 void up(int l,int r,int w)

13 {

14     lm[w] = min(lm[w<<1],lm[w<<1|1]);

15     sm[w] = max(sm[w<<1],sm[w<<1|1]);

16 }

17 void build(int l,int r,int w)

18 {

19     if(l==r)

20     {

21         scanf("%d",&s[w]);

22         lm[w] = sm[w] = s[w];

23         return ;

24     }

25     int m = (l+r)>>1;

26     build(l,m,w<<1);

27     build(m+1,r,w<<1|1);

28     up(l,r,w);

29 }

30 int query1(int a,int b,int l,int r,int w)

31 {

32     if(a<=l&&b>=r)

33     {

34         return lm[w];

35     }

36     int m = (l+r)>>1,ans = INF;

37     if(a<=m)

38     ans = query1(a,b,l,m,w<<1);

39     if(b>m)

40     ans = min(ans,query1(a,b,m+1,r,w<<1|1));

41     return ans;

42 }

43 int query2(int a,int b,int l,int r,int w)

44 {

45     if(a<=l&&b>=r)

46     {

47         return sm[w];

48     }

49     int m = (l+r)>>1,ans = -INF;

50     if(a<=m)

51     ans = query2(a,b,l,m,w<<1);

52     if(b>m)

53     ans = max(ans,query2(a,b,m+1,r,w<<1|1));

54     return ans;

55 }

56 int main()

57 {

58     int i,n,k;

59     while(scanf("%d%d",&n,&k)!=EOF)

60     {

61         build(1,n,1);

62         o = 1;

63         mi[1] = query1(1,k,1,n,1);

64         ma[1] = query2(1,k,1,n,1);

65         for(i = 2; i <= n-k+1 ; i++)

66         {

67             o++;

68             mi[o] = query1(i,i+k-1,1,n,1);

69             ma[o] = query2(i,i+k-1,1,n,1);

70         }

71         for(i = 1; i < o ; i++)

72         printf("%d ",mi[i]);

73         printf("%d\n",mi[o]);

74         for(i = 1; i < o ; i++)

75         printf("%d ",ma[i]);

76         printf("%d\n",ma[o]);

77     }

78     return 0;

79 }

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