public int ReversePairs(int[] nums)
{
SortedSet <long> allNumbers = new SortedSet <long>();
foreach (int num in nums)
{
allNumbers.Add((long)num);
allNumbers.Add(2 * (long)num);
}
Dictionary <long, int> values = new Dictionary <long, int>();
int index = 0;
foreach (var num in allNumbers)
{
values.Add(num, index);
index++;
}
int res = 0;
BIT bit = new BIT(values.Count);
for (int i = 0; i < nums.Length; i++)
{
int left = values[(long)nums[i] * 2];
int right = values.Count - 1;
res += bit.Query(right + 1) - bit.Query(left + 1);
bit.Update(values[(long)nums[i]] + 1, 1);
}
return(res);
}
static int[] Solve(int n, long[] a)
{
var res = new int[n];
BIT <long> bit = new BIT <long>(n + 1, 0, (x, y) => x + y);
for (int i = 0; i < bit.Size; i++)
{
bit.Operate(i, i);
}
for (int i = a.Length - 1; i >= 1; i--)
{
int valid = n + 1;
int invalid = -1;
while (valid - invalid > 1)
{
var mid = (valid + invalid) / 2;
if (a[i] < bit.Query(mid))
{
valid = mid;
}
else
{
invalid = mid;
}
}
res[i] = valid;
bit.Operate(res[i], -res[i]);
}
res[0] = (int)bit.Query(bit.Size - 1);
return(res);
}
public static void Main()
{
var n = NextInt;
var k = NextInt;
var reducedA = new int[n];
for (int i = 0; i < n; i++)
{
reducedA[i] = NextInt - k;
}
var accum = new long[n + 1];
for (int i = 0; i < reducedA.Length; i++)
{
accum[i + 1] = accum[i] + reducedA[i];
}
//var compressDict = accum.Distinct().OrderBy(x => x).Select((elem, ind) => new Tuple { Item1 = elem, Item2 = ind }).ToDictionary(x => x.Item1, x => x.Item2);
var distincted = accum.Distinct().ToArray();
Array.Sort(distincted);
long res = 0;
BIT <int> bit = new BIT <int>(distincted.Length, 0, (x, y) => x + y);
for (int i = 0; i < accum.Length; i++)
{
var ind = Array.BinarySearch(distincted, accum[i]);
res += bit.Query(ind);
bit.Operate(ind, 1);
}
Console.WriteLine(res);
}
public static void Main()
{
var n = NextInt;
BIT <int> bit = new BIT <int>(100001, 0, Max);
foreach (var boxes in Enumerable.Repeat(0, n).Select(_ => new Box()
{
X = NextInt, Y = NextInt
}).GroupBy(x => x.X).OrderBy(x => x.Key))
{
foreach (var item in boxes.Select(x => new { Pos = x.Y, Res = bit.Query(x.Y) }).ToArray())
{
bit.Operate(item.Pos, item.Res + 1);
}
}
var res = bit.Query(bit.Size);
Console.WriteLine(res);
}
static void Main()
{
int n = NextInt;
var q = NextInt;
BIT <int> bit = new BIT <int>(n + 1, 0, (x, y) => x + y);
StringBuilder builder = new StringBuilder();
for (int i = 0; i < q; i++)
{
if (NextInt == 0)
{
bit.Operate(NextInt, NextInt);
}
else
{
builder.AppendLine((-bit.Query(NextInt - 1) + bit.Query(NextInt)).ToString());
}
}
Console.Write(builder.ToString());
}
public static void Main()
{
int n = int.Parse(Console.ReadLine());
var a = Console.ReadLine().Split().Select(int.Parse).ToArray();
var compress = a.Distinct().OrderByDescending(x => x).Select((Elem, Count) => new { Elem, Count }).ToDictionary(x => x.Elem, x => x.Count);
long res = 0;
for (int i = 0; i < n; i++)
{
//一点加算/区間和が可能なBinary Indexed Tree(BIT)
BIT <int> bit = new BIT <int>(compress.Count, 0, (x, y) => x + y);
for (int k = i + 1; k < n; k++)
{
//max(a_i, a_k)より大きい要素の数の和(座標圧縮先のindexに直してからquery)
res += bit.Query(compress[Max(a[i], a[k])]);
//今の点についてBITに追加
bit.Operate(compress[a[k]], 1);
}
}
Console.WriteLine(res);
}
static void Main()
{
BIT <int> bit = new BIT <int>(NextInt + 1, 0, (x, y) => x + y);
int q = NextInt;
StringBuilder builder = new StringBuilder();
for (int i = 0; i < q; i++)
{
if (NextInt == 0)
{
var l = NextInt;
var r = NextInt;
var x = NextInt;
bit.Operate(l, x);
bit.Operate(r + 1, -x);
}
else
{
builder.AppendLine(bit.Query(NextInt).ToString());
}
}
Console.Write(builder.ToString());
}
static void Validate(int n)
{
Random rng = new Random();
var res = Enumerable.Range(1, n).OrderBy(x => rng.Next()).ToArray();
BIT <long> bit = new BIT <long>(n + 1, 0, (x, y) => x + y);
long[] a = new long[n];
for (int i = 0; i < res.Length; i++)
{
a[i] = bit.Query(res[i]);
bit.Operate(res[i], res[i]);
}
System.Diagnostics.Stopwatch watch = new System.Diagnostics.Stopwatch();
watch.Start();
var ans = Solve(n, a);
Console.WriteLine(watch.ElapsedMilliseconds);
if (res.Zip(ans, (x, y) => x != y).Any(x => x))
{
Console.WriteLine(string.Join(" ", res));
Console.WriteLine(string.Join(" ", Solve(n, a)));
Console.WriteLine(string.Join(" ", a));
}
}