daily-temperatures.py

# Time:  O(n)
# Space: O(n)

class Solution(object):
    def dailyTemperatures(self, temperatures):
        """
        :type temperatures: List[int]
        :rtype: List[int]
        """
        result = [0] * len(temperatures)
        stk = []
        for i in xrange(len(temperatures)):
            while stk and \
                  temperatures[stk[-1]] < temperatures[i]:
                idx = stk.pop()
                result[idx] = i-idx
            stk.append(i)
        return result