OJ-Problems-Source/hihoCoder/1068.cpp

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2016-08-11 10:18:19 +08:00
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <algorithm>
#include <cmath>
using namespace std;
const int MAXN = 1000005;
int n,ndev;
int a[MAXN];
const int MAXDEV = 25;
int minsum[MAXN][MAXDEV];
void RMQ() //预处理->O(nlogn)
{
for(int j = 1; j <= ndev; ++j)
for(int i = 1; i <= n; ++i)
if(i + (1 << j) - 1 <= n)
{
//maxsum[i][j] = max(maxsum[i][j - 1], maxsum[i + (1 << (j - 1))][j - 1]);
minsum[i][j] = min(minsum[i][j - 1], minsum[i + (1 << (j - 1))][j - 1]);
}
}
int RMQ(int i,int j)
{
int k=log2( j - i + 1);
//return max(maxsum[i ][ k], maxsum[ j - 2 ^ k + 1][ k]);
return min(minsum[i ][ k], minsum[ j - (1<<k) + 1][ k]);
}
void Init()
{
for(int i=1;i<=n;i++)
{
minsum[i][0]=a[i];
}
}
int main()
{
scanf("%d",&n);
ndev=0;
int p=n;
if(p&1) p++;
while(p>1)
{
p>>=1;
ndev++;
}
for(int i=1;i<=n;i++)
{
scanf("%d",&a[i]);
}
Init();
RMQ();
int t;
scanf("%d",&t);
for(int i=0;i<t;i++)
{
int L,R;
scanf("%d %d",&L,&R);
int ans=RMQ(L,R);
printf("%d\n",ans);
}
return 0;
}