数组_leetcode167

#coding=utf-8
# 解题思路： 关键点：二分查找  20190302 找工作期间

class Solution(object):
    def twoSum(self, numbers, target):
        """
        :type numbers: List[int]
        :type target: int
        :rtype: List[int]
        """
        if not numbers:
            return

        start = 0
        end = len(numbers)-1

        for i in range(len(numbers)):
            j =  self.binarySearch(numbers,start,end ,target-numbers[i])

            if i != j and j != -1:
                if i < j:
                    return [i+1,j+1]
                else:
                    return []
        pass


    def binarySearch(self,alist,start,end,target ):

        if start > end :
            return -1
        while(start <= end):
            mid = start + (end-start)/2
            if alist[mid] == target:
                return mid
            elif target > alist[mid]:
                start = mid + 1
            else:
                end = mid -1



        return -1



class Solution2(object):
    def twoSum(self, numbers, target):
        """
        :type numbers: List[int]
        :type target: int
        :rtype: List[int]
        """
        if not numbers:
            return

        start = 0
        end = len(numbers)-1

        while start < end :

            if numbers[start] + numbers[end] == target:
                return [start+1,end+1]

            elif numbers[start] + numbers[end] > target:
                end -= 1

            else:
                start += 1





numbers = [2, 7, 11, 15]
target = 9

s = Solution2()

print s.twoSum(numbers,9)