poj 3368 rmq ***

题意：给出n个数和Q个询问（l,r)，对于每个询问求出(l,r)之间连续出现次数最多的次数。

 1 #include<cstdio>

 2 #include<iostream>

 3 #include<algorithm>

 4 #include<cstring>

 5 #include<cmath>

 6 #include<queue>

 7 #include<map>

 8 using namespace std;

 9 #define MOD 1000000007

10 const int INF=0x3f3f3f3f;

11 const double eps=1e-5;

12 typedef long long ll;

13 #define cl(a) memset(a,0,sizeof(a))

14 #define ts printf("*****\n");

15 int n,m,tt;

16 const int MAXN = 100005;

17 int dp[MAXN][20];

18 int mm[MAXN];

19 //初始化RMQ, b数组下标从1开始，从0开始简单修改

20 void initRMQ(int n,int b[])

21 {

22 mm[0] = -1;

23 for(int i = 1; i <= n;i++)

24 {

25 mm[i] = ((i&(i-1)) == 0)?mm[i-1]+1:mm[i-1];

26 dp[i][0] = b[i];

27 }

28 for(int j = 1; j <= mm[n];j++)

29 for(int i = 1;i + (1<<j) -1 <= n;i++)

30 dp[i][j] = max(dp[i][j-1],dp[i+(1<<(j-1))][j-1]);

31 }

32 //查询最大值

33 int rmq(int x,int y)

34 {

35 int k = mm[y-x+1];

36 return max(dp[x][k],dp[y-(1<<k)+1][k]);

37 }

38 int a[MAXN],f[MAXN];

39 int main()

40 {

41     int i,j,k;

42     #ifndef ONLINE_JUDGE

43     freopen("1.in","r",stdin);

44     #endif

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

46     {

47         if(n==0)  break;

48         scanf("%d",&m);

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

50         {

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

52             f[1]=1;

53             if(i!=1)

54             {

55                 if(a[i]==a[i-1])

56                 {

57                     f[i]=f[i-1]+1;

58                 }

59                 else

60                     f[i]=1;

61             }

62         }

63         /*for(i=1;i<=n;i++)

64         {

65             printf("%d ",f[i]);

66         }

67         printf("\n");*/

68         initRMQ(n,f);

69         while(m--)

70         {

71             int uu,v;

72             scanf("%d%d",&uu,&v);

73             int u=uu;

74             while(u<=v&&a[u]==a[u-1])

75             {

76                 u++;

77             }

78             int ans=rmq(u,v);

79             ans=max(u-uu,ans);

80             printf("%d\n",ans);

81         }

82     }

83 }