RMQ问题

#include<cstdio>
#include<cstring>
#include<vector>
#include<algorithm>
#include<iostream>
using namespace std;
const int N = 1e5 + 10;
int n, tot, Q;
int dp
[20];
int num
, cnt
, Left
, Right
;
void RMQ_Init()
{
memset(dp, 0, sizeof(dp));
for(int i = 1; i <= tot; i++)
dp[i][0] = cnt[i];
for(int j = 1; (1<<j) <= n; j++)
for(int i = 1; i + (1<<j) - 1 <= tot; i++)
dp[i][j] = max(dp[i][j-1], dp[i+(1<<(j-1))][j-1]);
}
int RMQ(int L, int R)
{
if(L > R)
return 0;
int k = 0;
while((1<<(k+1)) <= R - L + 1) k++;
return max(dp[L][k], dp[R-(1<<k)+1][k]);
}
int main()
{
int v, last_v, i;
while(~scanf("%d",&n))
{
if(n == 0) break;
scanf("%d",&Q);
tot = 0;
memset(Left, 0, sizeof(Left));
memset(Right, 0, sizeof(Right));
memset(cnt, 0, sizeof(cnt));
for(i = 1; i <= n; i++)
{
scanf("%d",&v);
if(i == 1)
{
++tot;
last_v = v;
Left[tot] = 1;
}
if(last_v == v)
{
num[i] = tot;
cnt[tot]++;
Right[tot]++;
}
else
{
num[i] = ++tot;
cnt[tot]++;
Left[tot] = Right[tot] = i;
last_v = v;
}
}
RMQ_Init();
int L, R;
for(int i = 0; i < Q; i++)
{
scanf("%d%d",&L,&R);
if(num[L] == num[R])
printf("%d\n", R - L + 1);
else
{
int tmp1 = Right[num[L]] - L + 1;
int tmp2 = R - Left[num[R]] + 1;
int tmp3 = RMQ(num[L] + 1, num[R] - 1);
printf("%d\n",max(tmp1, max(tmp2, tmp3)));
}
}
}
return 0;
}