School Dance - Implementation

Here is Kuhn's algorithm for School Dance:

function schoolDance(n, m, preferences):
    adj = build adjacency list for boys
    match = array of size m + 1, all 0  // match[girl] = boy
    answer = 0

    function dfs(boy, visited):
        for girl in adj[boy]:
            if visited[girl]:
                continue
            visited[girl] = true

            // If girl is unmatched or her current match can find another
            if match[girl] == 0 or dfs(match[girl], visited):
                match[girl] = boy
                return true
        return false

    for boy from 1 to n:
        visited = array of size m + 1, all false
        if dfs(boy, visited):
            answer = answer + 1

    // Reconstruct pairs
    pairs = empty list
    for girl from 1 to m:
        if match[girl] != 0:
            pairs.append((match[girl], girl))

    print answer
    print pairs

Time: $O(VE)$. Space: $O(V)$.