回溯法

子集樹

程式碼如下：

def constraint():
    # 約束函式
    return True


def bound():
    # 限界函式
    return True


def backtracing(t, lst, temp):
    # 回溯法函式
    size = len(lst)
    if t == size:
        print(temp)
    else:
        for i in range(0, size):
            temp[t] = lst[i]
            if constraint() and
 
 bound():
                backtracing(t+1, lst, temp)  # 遞迴


if __name__ == '__main__':
    A = ['A', 'B', 'C']
    B = ['A', 'B', 'C']
    backtracing(0, A, B)

執行結果：

排列樹

程式碼如下：

def constraint():
    # 約束函式
    return True


def bound():
    # 限界函式
    return True


def backtracing(t, lst):
 

    # 回溯法函式
    size = len(lst)
    if t == size:
        print(lst)
    else:
        for i in range(t, size):
            (A[t], A[i]) = (A[i], A[t])  # 交換第i個
            if constraint() and bound():
                backtracing(t+1, lst)
            (A[t], A[i]) = (A[i], A[t])


if __name__ == '__main__'
 
:
    A = ['A', 'B', 'C']
    backtracing(0, A)

輸出結果：