for j in range(n): if not any(abs(j-state[k])==k-i for k, i in enumerate(state)):

这是 Python 代码的一部分。它是用于 N 皇后问题的解决方案中的一小段代码。其中，n 是棋盘的大小，state 是一个列表，表示当前每一行的皇后所在的列数。

在这段代码中，for 循环遍历了每一列，if 语句中的表达式是用来检查在当前列是否有与前面的皇后冲突的皇后。如果这个表达式的结果为 False，说明当前列可以放置一个皇后，没有冲突。如果所有列都检查完毕，程序能够顺利执行完毕，说明找到了一组可行的解决方案。

其中，enumerate 函数是 Python 内置函数，用来遍历一个序列（如列表、元组或字符串），同时返回每个元素的序号和值，这里用来获取每个皇后所在的行号和列号。abs 函数是计算一个数的绝对值。

相关问题

用代码解决这个问题The program committee of the school programming contests, which are often held at the Ural State University, is a big, joyful, and united team. In fact, they are so united that the time spent together at the university is not enough for them, so they often visit each other at their homes. In addition, they are quite athletic and like walking. Once the guardian of the traditions of the sports programming at the Ural State University decided that the members of the program committee spent too much time walking from home to home. They could have spent that time inventing and preparing new problems instead. To prove that, he wanted to calculate the average distance that the members of the program committee walked when they visited each other. The guardian took a map of Yekaterinburg, marked the houses of all the members of the program committee there, and wrote down their coordinates. However, there were so many coordinates that he wasn't able to solve that problem and asked for your help. The city of Yekaterinburg is a rectangle with the sides parallel to the coordinate axes. All the streets stretch from east to west or from north to south through the whole city, from one end to the other. The house of each member of the program committee is located strictly at the intersection of two orthogonal streets. It is known that all the members of the program committee walk only along the streets, because it is more pleasant to walk on sidewalks than on small courtyard paths. Of course, when walking from one house to another, they always choose the shortest way. All the members of the program committee visit each other equally often. Input The first line contains the number n of members of the program committee (2 ≤ n ≤ 105). The i-th of the following n lines contains space-separated coordinates xi, yi of the house of the i-th member of the program committee (1 ≤ xi, yi ≤ 106). All coordinates are integers. Output Output the average distance, rounded down to an integer, that a member of the program committee walks from his house to the house of his colleague.

Sure, I can help you with that. Here's one possible solution in Python:

import math

n = int(input())
x_coords = []
y_coords = []

for i in range(n):
    x, y = map(int, input().split())
    x_coords.append(x)
    y_coords.append(y)

x_coords.sort()
y_coords.sort()

x_median = x_coords[n // 2]
y_median = y_coords[n // 2]

total_distance = 0

for i in range(n):
    total_distance += abs(x_coords[i] - x_median) + abs(y_coords[i] - y_median)

average_distance = total_distance // n

print(average_distance)

The idea here is to find the median x-coordinate and the median y-coordinate of all the houses, since these will be the coordinates of the "center" of the city. Then, we calculate the total distance each member of the program committee will have to walk to get to their colleague's house, by adding up the Manhattan distances between their own coordinate and the median coordinates. Finally, we divide the total distance by the number of committee members to get the average distance, rounded down to an integer. Note that we don't actually need to calculate the square root of the distances, since we only care about the integer value.

I hope this helps! Let me know if you have any questions.