圖的深度遍歷

class list_node:
    def __init__(self):
        self.val = 0
        self.next = None


head = [list_node()] * 9  # 聲明一個節點類型的鏈表數組

run = [0] * 9


def dfs(current):  # 深度優先函數
    run[current] = 1
    print('[%d] ' % current, end='')
    ptr = head[current].next
    while ptr != None:
        if run[ptr.val] == 0:  # 若是頂點還沒有遍歷，
            dfs(ptr.val)  # 就進行dfs的遞歸調用
        ptr = ptr.next


# 聲明圖的邊線數組
data = [[1, 2], [2, 1], [1, 3], [3, 1], \
        [2, 4], [4, 2], [2, 5], [5, 2], \
        [3, 6], [6, 3], [3, 7], [7, 3], \
        [4, 8], [8, 4], [5, 8], [8, 5], \
        [6, 8], [8, 6], [8, 7], [7, 8]]
for i in range(1, 9):  # 共有八個頂點
    run[i] = 0  # 把全部頂點設置成還沒有遍歷過
    head[i] = list_node()
    head[i].val = i  # 設置各個鏈表頭的初值
    head[i].next = None
    ptr = head[i]  # 設置指針指向鏈表頭
    for j in range(20):  # 二十條邊線
        if data[j][0] == i:  # 若是起點和鏈表頭相等，則把頂點加入鏈表
            newnode = list_node()
            newnode.val = data[j][1]
            newnode.next = None
            while True:
                ptr.next = newnode  # 加入新節點
                ptr = ptr.next
                if ptr.next == None:
                    break

print('圖的鄰接表內容：')  # 打印圖的鄰接表內容
for i in range(1, 9):
    ptr = head[i]
    print('頂點 %d=> ' % i, end='')
    ptr = ptr.next
    while ptr != None:
        print('[%d] ' % ptr.val, end='')
        ptr = ptr.next
    print()
print('深度優先遍歷的頂點：')  # 打印深度優先遍歷的頂點
dfs(1)
print()