public override IEnumerable <object> Solve(TextReader inputStream)
{
var n = inputStream.ReadInt();
var p = inputStream.ReadIntArray();
var indices = new int[n];
long sum = 0;
for (int i = 0; i < p.Length; i++)
{
indices[p[i] - 1] = i + 1;
}
var bit = new BinaryIndexedTree(n + 2);
bit[0] += 2;
bit[n + 1] += 2;
for (int pi = n; pi > 0; pi--)
{
var index = indices[pi - 1];
var left = bit.Sum(..index);
var right = bit.Sum((index + 1)..);
var left2 = bit.GetLowerBound(left - 1) + 1;
var left1 = bit.GetLowerBound(left) + 1;
var right1 = bit.GetLowerBound(left + 1);
var right2 = bit.GetLowerBound(left + 2);
sum += (long)(left1 - left2) * (right1 - index) * pi;
sum += (long)(index - left1 + 1) * (right2 - right1) * pi;
bit[index]++;
}
yield return(sum);
}
public override IEnumerable <object> Solve(TextReader inputStream)
{
var bit = new BinaryIndexedTree(2000001);
var queries = inputStream.ReadInt();
for (int q = 0; q < queries; q++)
{
var(type, x) = inputStream.ReadValue <int, int>();
if (type == 1)
{
bit[x]++;
}
else
{
var index = bit.GetLowerBound(x);
bit[index]--;
yield return(index);
}
}
}
