二分图最大匹配数量，匈牙利算法求解 python

二分图最大匹配数量，匈牙利算法求解 python，本质上是找增广回路

"""
# File       : hungary.py
# Time       ：2022/8/28 21:08
# Author     ：notomato
# Description：
# 
"""
'''


'''
# 六个点
# 第i个坐标存他相邻的点

from collections import  defaultdict
n = 8
arr = [1,2,2,3,3,5,1]

vis = [0 for _ in range(n+1)]
g = defaultdict(list)
conn = defaultdict(bool)
for i, v in enumerate(arr):
    g[i+2].append(v)
    g[v].append(i+2)
    conn[(v, i + 2)] = True
    conn[(i+2, v)] = True


# 二分图
two = [set(), set()]
q = [1]
vis[1] = True
level = 0
# 分为两部分，按照树的层来分的
while len(q) > 0:
    tmp = []
    for nxt in q:
        two[level&1].add(nxt)
        for nnxt in g[nxt]:
            if not vis[nnxt]:
                vis[nnxt] = True
                tmp.append(nnxt)
    q = tmp
    level += 1

print(two)
a,b = list(two[0]), list(two[1])

def match(x):
    for y in b:
        if conn[(x,y)] and not vised[y]:
            vised[y] = 1
            if connb[y] == 0 or match(connb[y]) != 0:
                connb[y] = x
                return 1
    return 0


ans = 0
connb = defaultdict(int)
for x in a:
    vised = defaultdict(int)
    if match(x):
        ans += 1
print(ans)
print(connb)