此代码有什么问题?无法使用二进制搜索在连续数组中搜索缺少的数字。
a = [1,2,3,4,5,7,8]
lent = len(a)
beg =0
end = lent-1
while beg < end:
mid = (beg + end) / 2
if (a[mid]-a[beg])==(mid - beg):
beg = mid + 1
else:
end = mid -1
if(beg == end):
mid = (beg + end) / 2
print "missing"
print a[0]+ beg
更新1:是的,还有一个错误。你是对的。这是更新版本
尝试此变体:
a = [1,2,3,4,5,7,8]
lent = len(a)
beg =0
end = lent-1
while beg < end:
mid = (beg + end) / 2
if (a[mid]-a[beg])==(mid - beg):
beg = mid
else:
end = mid
if abs(beg-end) <= 1:
print "missing: %s" % (a[0] + max(beg, mid),)
结果:
missing: 6
另外,尝试使用函数,这样您就可以轻松地在不同的列表上测试和调试代码:
def find_missing(a):
lent = len(a)
beg =0
end = lent-1
while beg < end:
mid = (beg + end) / 2
if (a[mid]-a[beg])==(mid - beg):
beg = mid
else:
end = mid
if abs(beg-end) <= 1:
return a[0] + max(beg, mid)
a = [1,2,3,4,5,7,8]
print find_missing(a)
a = [1,3,4,5,6]
print find_missing(a)
a = [1,2,3,4,5,7,8,9,10]
print find_missing(a)
结果:
6
2
6