new_contents: class Solution(object):
      def coinChange(self, coins, amount):
          """
          :type coins: List[int]
          :type amount: int
          :rtype: int
          """
          min_count = [0] * (amount + 1)
          for c in coins:
              if c <= amount:
                  min_count[c] = 1
          for i in xrange(min(coins), amount + 1):
              next_min = None
              for c in coins:
                  if i == c or (i > c and min_count[i - c] > 0):
                      t = min_count[i - c] + 1
                      if next_min is None or t < next_min:
                          next_min = t
              if next_min is not None:
                  min_count[i] = next_min
  
          if min_count[amount] == 0 and amount > 0:
              return -1
          else:
              return min_count[amount]
  
subject: Add py solution for 322. Coin Change