search-insert-position.py

# Time:  O(logn)
# Space: O(1)
#
# Given a sorted array and a target value, return the index if the target is found.
# 
# If not, return the index where it would be if it were inserted in order.
# 
# You may assume no duplicates in the array.
# 
# Here are few examples.
# [1,3,5,6], 5 -> 2
# [1,3,5,6], 2 -> 1
# [1,3,5,6], 7 -> 4
# [1,3,5,6], 0 -> 0
#

class Solution:
    # @param A, a list of integers
    # @param target, an integer to be inserted
    # @return integer
    def searchInsert(self, A, target):
        low, high = 0, len(A) - 1
        
        while low <= high:
            mid = low + (high - low) / 2
            if A[mid] == target:
                return mid
            elif A[mid] < target:
                low = mid + 1
            else:
                high = mid - 1
        
        return low

if __name__ == "__main__":
    print Solution().searchInsert([1, 3, 5, 6], 5)
    print Solution().searchInsert([1, 3, 5, 6], 2)
    print Solution().searchInsert([1, 3, 5, 6], 7)
    print Solution().searchInsert([1, 3, 5, 6], 0)