st函数--区间最大最小值

void make_st()//st预处理
{
for(int i = 1;i <= n;i++){
minn[i][0] = ori[i];
maxx[i][0] = ori[i];
}
for(int j = 1;(1 << j) <= n;j++)//递推求区间最大最小
for(int i = 1;i + (1 << j) - 1 <= n;i++)
{
minn[i][j] = min(minn[i][j - 1],minn[i + (1 << (j - 1))][j - 1]);
maxx[i][j] = max(maxx[i][j - 1],maxx[i + (1 << (j - 1))][j - 1]);
}
}

int query_max(int l,int r)//O（1）查询
{
int k = 0;
while((1 << (k + 1)) <= r - l + 1)k++;
return max(maxx[l][k],maxx[r - (1 << k) + 1][k]);
}

int query_min(int l,int r)
{
int k = 0;
while((1 << (k + 1)) <= r - l + 1)k++;
return min(minn[l][k],minn[r - (1 << k) + 1][k]);
}