1346. 检查整数及其两倍数是否存在

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class Solution:
    def checkIfExist(self, arr: List[int]) -> bool:
        # 暴力枚举方法
        # for i in range(len(arr)):
        #     for j_value in arr[i+1:]:
        #         if arr[i]==2*j_value or 2*arr[i]==j_value:
        #             return True
        # return False
        # 二分法
        arr.sort()
        while len(arr)>1:
            if arr[len(arr)-1]>=0: # 正数
                last = arr.pop()
                left = 0
                right = len(arr)-1
                while left<=right:
                    mid = (left+right)>>1
                    if 2*arr[mid]==last:
                        return True 
                    elif  2*arr[mid]>last:
                        right = mid-1
                    else:
                        left = mid+1
            if arr[len(arr)-1]<0:   # 负数 
                first = arr.pop(0)
                left = 0
                right = len(arr)-1
                while left<=right:
                    mid = (left+right)>>1
                    if 2*arr[mid]==first:
                        return True 
                    elif  2*arr[mid]>first:
                        right = mid-1
                    else:
                        left = mid+1
        return False