标签：function you clu style query color log logs param
Given an integer array nums, find the sum of the elements between indices i and j (i ≤ j), inclusive.
Example:
Given nums = [-2, 0, 3, -5, 2, -1] sumRange(0, 2) -> 1 sumRange(2, 5) -> -1 sumRange(0, 5) -> -3Note:
想了想怎么可能有这么简单的题
那么重点在这句：There are many calls to sumRange function.
因此要考虑效率，那么自然考虑动态规划
class NumArray { private int[] sums; public NumArray(int[] nums) { sums = new int[nums.length]; for(int i=0;i<nums.length;i++) { if(i==0) sums[i]=nums[i]; sums[i] = sums[i-1]+nums[i]; } } public int sumRange(int i, int j) { if(i==0) return sums[j]; return sums[j]-sums[i-1]; } } /** * Your NumArray object will be instantiated and called as such: * NumArray obj = new NumArray(nums); * int param_1 = obj.sumRange(i,j); */
标签：function you clu style query color log logs param
原文地址：http://www.cnblogs.com/swuwyb/p/7722979.html
