【leetcode❤python】 303. Range Sum Query - Immutable

#-*- coding: UTF-8 -*-
#Tags:dynamic programming,sumRange(i,j)=sum(j)-sum(i-1)
class NumArray(object):
    sums=[]
    def __init__(self, nums):
        """
        initialize your data structure here.
        :type nums: List[int]
        """
        self.nums=nums
        self.sums=nums
        for i in xrange(1,len(self.sums)):
            self.sums[i]+=self.sums[i-1]
        

    def sumRange(self, i, j):
        """
        sum of elements nums[i..j], inclusive.
        :type i: int
        :type j: int
        :rtype: int
        """
        if i>j or j>=len(self.sums):return 0
       
        return self.sums[j] if i==0 else (self.sums[j]-self.sums[i-1])

numArray = NumArray([-2, 0, 3, -5, 2, -1])
print numArray.sumRange(3,4)