N = 25皇后问题。使用基本的爬山算法。

以下是一个使用基本的爬山算法解决25皇后问题的示例代码：

import random

# 检查是否存在冲突
def has_conflict(state, row, col):
    for i in range(row):
        if state[i] == col or state[i] - i == col - row or state[i] + i == col + row:
            return True
    return False

# 计算冲突数量
def count_conflicts(state):
    conflicts = 0
    for i in range(len(state)):
        for j in range(i+1, len(state)):
            if has_conflict(state, i, state[i]) or has_conflict(state, j, state[j]):
                conflicts += 1
    return conflicts

# 爬山算法
def hill_climbing(n):
    # 初始化棋盘
    current_state = [random.randint(0, n-1) for _ in range(n)]
    current_conflicts = count_conflicts(current_state)

    while True:
        next_state = list(current_state)
        next_conflicts = current_conflicts
        best_conflicts = current_conflicts

        # 寻找下一个最优解
        for col in range(n):
            for row in range(n):
                if current_state[row] != col:
                    next_state[row] = col
                    conflicts = count_conflicts(next_state)
                    if conflicts < best_conflicts:
                        best_conflicts = conflicts
                        next_conflicts = conflicts

            if best_conflicts < next_conflicts:
                break

        # 如果没有改进，返回当前解
        if best_conflicts >= current_conflicts:
            return current_state

        current_state = list(next_state)
        current_conflicts = best_conflicts

# 测试
solution = hill_climbing(25)
print("Solution: ", solution)
print("Conflicts: ", count_conflicts(solution))

此代码首先定义了两个辅助函数，has_conflict用于检查是否存在冲突，count_conflicts用于计算冲突数量。然后定义了hill_climbing函数，它使用爬山算法解决N皇后问题。最后，在测试部分调用hill_climbing函数解决25皇后问题，并打印解和冲突数量。