Appearance
question:A company organizes a corporate gifting event where employees can send gifts to their colleagues. There are n employees and each employee sends a gift to exactly one other employee. Some gifts may end up creating a cycle of gifts among a group of employees. You are given the information about who sends a gift to whom and your task is to find out the size of the largest cycle of gifts. -----Input:----- The first line contains an integer n, the number of employees. The next line contains n integers, where the i-th integer represents the employee number who sent a gift to the i-th employee (0-based index). -----Output:----- Print the size of the largest cycle of gifts. -----Constraints----- - 1 ≤ n ≤ 100 - 0 ≤ employee number < n -----Sample Input:----- 5 1 2 3 4 0 -----Sample Output:----- 5 # Explanation: The input means: - Employee 0 sends a gift to Employee 1. - Employee 1 sends a gift to Employee 2. - Employee 2 sends a gift to Employee 3. - Employee 3 sends a gift to Employee 4. - Employee 4 sends a gift to Employee 0. This creates a cycle, and the largest cycle involves all 5 employees. Hence, the size of the largest cycle is 5.
answer:def largest_gift_cycle(n, gifts): def find_cycle_length(start): visited = set() current = start length = 0 while current not in visited: visited.add(current) current = gifts[current] length += 1 return length if current == start else 0 max_cycle_length = 0 for i in range(n): current_cycle_length = find_cycle_length(i) max_cycle_length = max(max_cycle_length, current_cycle_length) return max_cycle_length
question:Given the roots of two binary trees, root1 and root2, return whether the leaf traversal of both trees is the same. A leaf node is a node with no children. The leaf traversal of a binary tree is an array of the values of the leaf nodes encountered in a left-to-right order. Example 1: Input: root1 = [3,5,1,6,2,9,8,null,null,7,4], root2 = [3,5,1,6,7,4,2,null,null,null,null,null,null,9,8] Output: true Explanation: The leaf nodes of both trees are [6, 7, 4, 9, 8]. Example 2: Input: root1 = [1,2,3], root2 = [1,3,2] Output: false Constraints: - The number of nodes in each tree will be in the range [1, 200]. - Both of the given trees will have values in the range [0, 200]. Note: You should explain your approach clearly in the code comments and write an efficient solution to handle the constraints.
answer:# Definition for a binary tree node. class TreeNode: def __init__(self, val=0, left=None, right=None): self.val = val self.left = left self.right = right def leafSimilar(root1, root2): Return whether the leaf traversal of both trees is the same. def dfs(root): if not root: return [] if not root.left and not root.right: return [root.val] return dfs(root.left) + dfs(root.right) return dfs(root1) == dfs(root2)
question:A network of computers can be represented as a directed acyclic graph (DAG) with n nodes and m directed edges. Each edge represents a direct data transfer link from one computer to another, and each computer can be represented by a node. The nodes are numbered from 1 to n. One of the computers (node 1) is infected with a virus and it can spread through the network following the directed edges. Your task is to determine the maximum amount of time it will take for the virus to potentially infect any computer in the network. Each edge has the same cost of time for the virus to travel from one node to another. -----Input----- The first line contains two integers n and m (2 ≤ n ≤ 10^5, 1 ≤ m ≤ 10^5) — the number of nodes and the number of edges in the graph. The next m lines each contain two integers u and v (1 ≤ u, v ≤ n, u ≠ v) indicating a directed edge from node u to node v. Note that some nodes may not be reachable from node 1. -----Output----- Print a single integer, the maximum time it will take for the virus starting from node 1 to reach any possibly infected computer. If no other computer can be infected, print 0. -----Examples----- Input 4 4 1 2 1 3 2 4 3 4 Output 2 Input 3 2 1 2 2 3 Output 2 Input 4 2 2 3 3 4 Output 0 -----Note----- In the first example, the virus can reach from node 1 to node 4 following either the path [1 -> 2 -> 4] or [1 -> 3 -> 4]. Each step between nodes costs 1 unit time, so the maximum time to infect any node is 2. In the second example, the maximum time from node 1 to node 3 is 2, as the virus travels [1 -> 2 -> 3]. In the third example, node 1 cannot reach any other nodes, so the output is 0.
answer:from collections import defaultdict, deque def max_infection_time(n, m, edges): # Create adjacency list adj_list = defaultdict(list) for u, v in edges: adj_list[u].append(v) # Initialize distances array distance = [-1] * (n + 1) distance[1] = 0 # Begin BFS from node 1 q = deque([1]) while q: current = q.popleft() for neighbor in adj_list[current]: if distance[neighbor] == -1: distance[neighbor] = distance[current] + 1 q.append(neighbor) # Find the maximum distance from node 1 to any node max_time = max(distance) return max_time if max_time != -1 else 0
question:You are given a string containing only lowercase alphabets. The task is to write a program that processes the string to generate a series of numbers based on the distance between consecutive characters in the alphabet. Rules 1. Each number in the series represents the absolute difference in the alphabetical positions of two consecutive characters in the string. 2. The position of 'a' is 1, 'b' is 2, 'c' is 3, ..., 'z' is 26. 3. If the string has only one character, the output should be an empty string. 4. If the string is empty, the output should be an empty string. Example Let’s consider the string "abc": The position of 'a' is 1. The position of 'b' is 2. The difference between 'a' and 'b' is |2 - 1| = 1. The position of 'c' is 3. The difference between 'b' and 'c' is |3 - 2| = 1. So, the output for the string "abc" should be: "1 1". Another example, for the string "az": The position of 'a' is 1. The position of 'z' is 26. The difference between 'a' and 'z' is |26 - 1| = 25. So, the output for the string "az" should be: "25". Note: - Do not use any built-in functions that directly solve the problem. - Write the function to return the result as a string of numbers separated by spaces. Function Signature `def distance_between_characters(s: str) -> str:`
answer:def distance_between_characters(s: str) -> str: Returns the series of absolute differences between the positions of consecutive characters in the alphabet. if len(s) < 2: return "" result = [] for i in range(len(s) - 1): pos1 = ord(s[i]) - ord('a') + 1 pos2 = ord(s[i + 1]) - ord('a') + 1 result.append(abs(pos2 - pos1)) return " ".join(map(str, result))