Submission #7110013

---

Source Code Expand

import sys
input = sys.stdin.readline
sys.setrecursionlimit(10 ** 7)

import numpy as np

MOD = 10**9 + 7

N,K = map(int,input().split())
A = np.array(input().split(), dtype=np.int64)

# 同じグループ内
def type_1():
    bl1 = A[:,None] > A[None,:]
    bl2 = np.arange(N,dtype=np.int64)[:,None] < np.arange(N,dtype=np.int64)[None,:]
    x = ((bl1 & bl2)*1).astype(np.int64).sum() % MOD
    return x*K%MOD

def type_2():
    # グループ間
    counter = np.bincount(A)
    cum = counter.cumsum()
    larger = N-cum
    x = (larger * counter % MOD).sum() % MOD
    y = K*(K-1)//2 % MOD
    return x*y%MOD

answer = (type_1() + type_2()) % MOD
print(answer)

Submission Info

Judge Result