遗传算法之背包问题

题目引用：https://zhuanlan.zhihu.com/p/28328304

 

def gen():
    #print(gen_grade([0, 1, 1, 0, 1, 1]))
    seeds = [[1,0,0,1,1,0], [0,0,1,1,1,0],[0,1,0,1,0,0],[0,1,1,0,0,1]]
    count_down = 1000
    while count_down > 0:
        grade_table = [(seed,gen_grade(seed)) for seed in seeds]
        best = max(grade_table,key = lambda x:x[1])
        print(best)
        # print(seeds)
        dad = survival(grade_table)
        mom = survival([(s,g) for s,g in grade_table if s != dad])
        seeds = [dad, mom] + off_spring(dad, mom) +[best[0]]
        # print(seeds)
        count_down -= 1


def off_spring(dad, mom):
    bro, sis = dad[:3] + mom[3:],mom[:3] + dad[3:]
    #变异
    r =  random.randint(0,5)
    monster = bro.copy()
    # print(r, monster)
    monster[r] = 1 if monster[r] == 0 else 0
    # print(monster)
    return [bro, sis, monster]

def survival(grade_table):
    total = sum([g for s,g, in grade_table])
    r = random.randint(0,total)
    total = 0
    for seed, g in grade_table:
        total += g
        if r <= total:
            return seed
    print (r, grade_table)



def gen_grade(chromosome):
    grade_table = [(15,15),(3,7),(2,10),(5,5),(9,8),(20,17)]
    grades = [grade_table[i] for i,x in enumerate(chromosome) if x > 0]
    if sum([w for w,s in grades]) > 30:
        return 0
    return sum([s for w,s in grades])