<每日一题>题目30:已知一个长度n的无序列表，元素均是数字，要求把所有间隔为d的组合找出来

def select_d(list,d):
    # list = sorted(list)
    sum = {}
    for i in list:
        if i+d in list:
            sum[i] = i+d
    return sum

list = [1,2,3,4,5,6,7,8,9,0,1213,12,31,2,13,21,21,221,11,10]
print(select_d(list,2))

　　运行结果:

{1: 3, 2: 4, 3: 5, 4: 6, 5: 7, 6: 8, 7: 9, 8: 10, 9: 11, 0: 2, 11: 13, 10: 12}