Recursion Power

Problem

Given a base a and an exponent b. Your task is to find ab. The value could be large enough. So, calculate ab % 1000000007.

Example One

{
"a": 2,
"b": 10
}

Output:

1024

Solution

function power(base, exponent) {
  if (exponent === 1) {
    return base;
  } else {
    return base * power(base ,exponent-1);
  }
}

Time and Space Complexity

Time: O(b).
Auxiliary space: O(1).
Total space: O(1).