题解
组合数第k小
https://ac.nowcoder.com/acm/contest/6221/A
第一题直接return k
第二题不会
第三题
def tree1(a):
res = 0
n = len(a)
for i in range(n):
if i2+1 < n:
res += (a[i] ^ a[i2+1])
print(a[i], a[i2+1])
if i2+2 < n:
res += (a[i] ^ a[i*2+2])
print(a[i], a[i * 2 + 2])
return res
