题解 | 左侧严格小于计数

from sys import stdin
from bisect import bisect_left
input = stdin.readline

class BIT:
    def __init__(self, size):
        self.n = size
        self.tree = [0] * (self.n + 1)
    def update(self, idx, delta):
        while idx <= self.n:
            self.tree[idx] += delta
            idx += idx & -idx
    def query(self, idx):
        res = 0
        while idx > 0:
            res += self.tree[idx]
            idx -= idx & -idx
        return res

n = int(input())
l = [int(i) for i in input().split()]
l2 = sorted(list(l))
m = len(l2)
BIT1 = BIT(m)
rank = []
for i in l:
    rank.append(bisect_left(l2, i)+1)
ans = []
for i in rank:
    ans.append(BIT1.query(i-1))
    BIT1.update(i, 1)
print(*ans)