Every number can be described in powers of 2. For example, `29 = 2^0 + 2^2 + 2^3 + 2^4`. Given an int `n`, return minimum number of additions and subtractions  of `2^i` to get `n`.\n\n**Example 1:**\n```\nInput: 15\nOutput: 2\nExplanation: 2^4 - 2^0 = 16 - 1 = 15\n```\n\n**Example 2:**\n```\nInput: 8\nOutput: 1\n```\n\n**Example 3:**\n```\nInput: 0\nOutput: 0\n```

Every number can be described in powers of 2. For example, 29 = 2^0 + 2^2 + 2^3 + 2^4. Given an int n, return minimum number of additions and subtractions  of 2