Leetcode 1820. Maximum Number of Accepted Invitations

Given an n×n boolean matrix where matrix[i][j] indicates whether person i would accept an invitation from person j, compute the largest number of accepted invitations under the constraint that each person can send at most one invitation and accept at most one. This is a maximum bipartite matching problem (solvable with DFS/Hopcroft–Karp or bitmask DP when n is small).