本文共 1974 字，大约阅读时间需要 6 分钟。

为了解决农农在浙农林大学行走时不踩进水坑的问题，我们需要设计一个程序来判断他能否在给定的水位下安全地从起点 (1, 1) 到达终点 (n, n)。我们可以使用二分查找配合广度优先搜索（BFS）来高效解决这个问题。

方法思路

解决代码

import sys
from collections import deque
def main():
    data = list(map(int, sys.stdin.read().split()))
    ptr = 0
    n = data[ptr]
    ptr += 1
    a = []
    for i in range(n):
        row = data[ptr:ptr + n]
        ptr += n
        a.append(row)
    
    def check(mid):
        visited = [[0] * (n + 1) for _ in range(n + 1)]
        q = deque()
        q.append((1, 1))
        visited[1][1] = 1
        if a[1][1] > mid or a[n][n] > mid:
            return False
        if n == 1:
            return True
        directions = [(-1, 0), (1, 0), (0, -1), (0, 1)]
        while q:
            x, y = q.popleft()
            for dx, dy in directions:
                nx = x + dx
                ny = y + dy
                if 1 <= nx <= n and 1 <= ny <= n:
                    if not visited[nx][ny] and a[nx][ny] <= mid:
                        if nx == n and ny == n:
                            return True
                        visited[nx][ny] = 1
                        q.append((nx, ny))
        return False
    low = 1
    high = 100000
    max_X = 0
    while low <= high:
        mid = (low + high) // 2
        can = check(mid)
        if can:
            max_X = mid
            low = mid + 1
        else:
            high = mid - 1
    q_num = data[ptr]
    ptr += 1
    for _ in range(q_num):
        x = data[ptr]
        ptr += 1
        if x <= max_X:
            print("Wuhu")
        else:
            print("Hmmm")
if __name__ == "__main__":
    main()

代码解释

转载地址：http://hpzgz.baihongyu.com/