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。

#include<cstdio>
#include<iostream>
#include<algorithm>
#include<cstring>
#include<cmath>
#include<queue>
#include<map>
using namespace std;
#define MOD 1000000007
const int INF=0x3f3f3f3f;
const double eps=1e-5;
typedef long long ll;
#define cl(a) memset(a,0,sizeof(a))
#define ts printf("*****
");
int n,m,tt;
const int MAXN = 100005;
int dp[MAXN][20];
int mm[MAXN];
//初始化RMQ, b数组下标从1开始，从0开始简单修改
void initRMQ(int n,int b[])
{
mm[0] = -1;
for(int i = 1; i <= n;i++)
{
mm[i] = ((i&(i-1)) == 0)?mm[i-1]+1:mm[i-1];
dp[i][0] = b[i];
}
for(int j = 1; j <= mm[n];j++)
for(int i = 1;i + (1<<j) -1 <= n;i++)
dp[i][j] = max(dp[i][j-1],dp[i+(1<<(j-1))][j-1]);
}
//查询最大值
int rmq(int x,int y)
{
int k = mm[y-x+1];
return max(dp[x][k],dp[y-(1<<k)+1][k]);
}
int a[MAXN],f[MAXN];
int main()
{
    int i,j,k;
    #ifndef ONLINE_JUDGE
    freopen("1.in","r",stdin);
    #endif
    while(scanf("%d",&n)!=EOF)
    {
        if(n==0)  break;
        scanf("%d",&m);
        for(i=1;i<=n;i++)
        {
            scanf("%d",&a[i]);
            f[1]=1;
            if(i!=1)
            {
                if(a[i]==a[i-1])
                {
                    f[i]=f[i-1]+1;
                }
                else
                    f[i]=1;
            }
        }
        /*for(i=1;i<=n;i++)
        {
            printf("%d ",f[i]);
        }
        printf("
");*/
        initRMQ(n,f);
        while(m--)
        {
            int uu,v;
            scanf("%d%d",&uu,&v);
            int u=uu;
            while(u<=v&&a[u]==a[u-1])
            {
                u++;
            }
            int ans=rmq(u,v);
            ans=max(u-uu,ans);
            printf("%d
",ans);
        }
    }
}