Ehab's REAL Number Theory Problem 前置知识 质数 分解质因数 无向无权图最小环<讲> Ehab's REAL Number Theory Problem/onCF 给 \(n\) 个数 \(a_i\)(\(a_i\) 的因数个数不超过 \(7\)),求最少选出多少个数,使得乘积为完全平方.无解输出 \(-1\). 数据范围:\(1\le n\le 10^5\),\(1\le a_i\le 10^6\). 没想到一场普通的 \(\texttt{CF}\) 比赛能…
原题链接在这里:https://leetcode.com/problems/graph-valid-tree/ 题目: Given n nodes labeled from 0 to n - 1 and a list of undirected edges (each edge is a pair of nodes), write a function to check whether these edges make up a valid tree. For example: Given n…
题目链接: B.Table 题意: \(n*m\)的矩阵使每个\(n*n\)矩阵里面准确包含\(k\)个点,问你有多少种放法. \((1 ≤ n ≤ 100; n ≤ m ≤ 10^{18}; 0 ≤ k ≤ n^2)\) 题解: - Let \(s_i\) number of points in the column \(i\). - Two neighboring squares are drawn at this picture, \(A\) is the number of point…