酷逼了 Pathetic Dog 第 304 场周赛

Pathetic Dog 全球排名第一
参考大神题解按自己的习惯改一些变量名

6132. 使数组中所有元素都等于零

class Solution:
    def minimumOperations(self, nums):
        return len(set(x for x in nums if x > 0))

6133. 分组的最大数量

尽然和分数没有关系，简化了大神的题解。

class Solution:
    def maximumGroups(self, grades: List[int]) -> int:
        pre = cnt = res = 0
        for i in range(len(grades)):
            cnt += 1
            if cnt > pre: # 比前一个个数大更新
                res += 1
                pre = cnt
                cnt = 0
        return res

6134. 找到离给定两个节点最近的节点

class Solution:
    def closestMeetingNode(self, edges: List[int], node1: int, node2: int) -> int:
        node1_dis = [-1] * len(edges)
        cur, dis = node1, 0
        while cur != -1:
            if node1_dis[cur] != -1: break
            node1_dis[cur] = dis
            cur = edges[cur]
            dis += 1

        node2_dis = [-1] * len(edges)
        cur, dis = node2, 0
        while cur != -1:
            if node2_dis[cur] != -1: break
            node2_dis[cur] = dis
            cur = edges[cur]
            dis += 1

        ans, best = -1, inf
        for i, (j, k) in enumerate(zip(node1_dis, node2_dis)):
            if j == -1 or k == -1: continue
            if max(j, k) < best:
                best = max(j, k)
                ans = i

        return ans

6135. 图中的最长环

class Solution:
    def longestCycle(self, edges: List[int]) -> int:
        ans = -1
        vis = set()
        for i in range(len(edges)):
            cnt = 0
            position = {
    }
            while i != -1 and i not in vis:
                position[i] = cnt
                vis.add(i)
                i = edges[i]
                cnt += 1
            if i != -1 and i in position:
                ans = max(ans, cnt - position[i])
        return ans