查找排序数组中缺少的数字序数、组中、数字

2023-09-03 11:19:40 作者:余生浅末

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

推荐答案

更新1:是的,还有一个错误。你是对的。这是更新版本

剑指 Offer 53 I. 在排序数组中查找数字 I

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