首选爬山法求解八皇后问题 python

爬山法是一种局部的贪婪搜索方法，它在搜索过程中容易陷入局部最优解而无法找到全局最优解。但是，通过一些变种方法，如随机重启爬山法和允许侧移的爬山法，可以提高爬山法求解八皇后问题的成功率。下面是一个使用Python实现的爬山法求解八皇后问题的示例代码：

import random

# 生成初始状态
def initial_state(n):
    state = [0] * n
    for i in range(n):
        state[i] = random.randint(0, n-1)
    return state

# 计算冲突数
def conflict_num(state):
    n = len(state)
    num = 0
    for i in range(n):
        for j in range(i+1, n):
            if state[i] == state[j] or abs(state[i]-state[j]) == j-i:
                num += 1
    return num

# 爬山法求解八皇后问题
def hill_climbing(n):
    state = initial_state(n)
    while True:
        conflicts = conflict_num(state)
        if conflicts == 0:
            return state
        next_state = state.copy()
        min_conflicts = conflicts
        for i in range(n):
            for j in range(n):
                if j != state[i]:
                    next_state[i] = j
                    new_conflicts = conflict_num(next_state)
                    if new_conflicts < min_conflicts:
                        min_conflicts = new_conflicts
                        state = next_state.copy()
        if min_conflicts >= conflicts:
            state = initial_state(n)

# 测试
if __name__ == '__main__':
    n = 8
    solution = hill_climbing(n)
    print(solution)