For two given positive numbers a and b. Find ab. Output your number modulus 109+7.
Example 1:
Input: a = 1, b = 1
Output: 1
Explanation: 11 % (109+7) = 1
​Example 2:
Input: a = 2, b = 5
Output: 32
Explanation: 25 % (109+7) = 32
Your Task:
You don't need to read input or print anything. Your task is to complete the function power() which takes a, b as inputs, and returns the answer.
Expected Time Complexity: O(log b) Expected Auxiliary Space: O(1)
