Submission #13539757

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Source Code Expand

import sys
import numpy as np
from numba import njit

read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines

@njit('(i4,i4[::1])', cache=True)
def solve(N, P):
    W = N + 2
    dp = np.zeros((W, W), np.int32)
    for _ in range(4):
        dp = dp.T[::-1]
        for n in range(1, (N + 1) // 2 + 1):
            dp[n, n:-n] = n
    filled = np.zeros_like(dp)
    filled[1:-1, 1:-1] = 1
    dp = dp.ravel()
    filled = filled.ravel()
    stack = np.empty_like(dp)
    ans = 0
    for n in P:
        n -= 1
        h, w = divmod(n, N)
        v = (h + 1) * W + (w + 1)
        ans += dp[v] - 1
        filled[v] = 0
        k = min(dp[v - 1], dp[v + 1], dp[v - W], dp[v + W])
        if dp[v] == k:
            return ans
        p = 0
        stack[0] = v
        dp[v] = k
        while p >= 0:
            v = stack[p]
            p -= 1
            for dx in (-1, 1, -W, W):
                w = v + dx
                k = dp[v] + filled[w]
                if dp[w] > k:
                    dp[w] = k
                    p += 1
                    stack[p] = w
    return ans

N = int(readline())
P = np.array(read().split(), np.int32)

print(solve(N, P))

Submission Info

Judge Result