标签：ant integer called class and ret man dice ted
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) -> -3
Note:
Solution 1:
class NumArray { int[] prefix; public NumArray(int[] nums) { if (nums == null || nums.length == 0) { return; } prefix = new int[nums.length]; prefix[0] = nums[0]; for(int i = 1; i < nums.length; i++) { prefix[i] = prefix[i - 1] + nums[i]; } } public int sumRange(int i, int j) { if (i == 0) { return prefix[j]; } return prefix[j] - prefix[i - 1]; } } /** * Your NumArray object will be instantiated and called as such: * NumArray obj = new NumArray(nums); * int param_1 = obj.sumRange(i,j); */
Solution 2:
class NumArray { int[] prefix; public NumArray(int[] nums) { prefix = new int[nums.length + 1]; for (int i = 0; i < nums.length; i++) { prefix[i + 1] = prefix[i] + nums[i]; } } public int sumRange(int i, int j) { return prefix[j + 1] - prefix[i]; } } /** * Your NumArray object will be instantiated and called as such: * NumArray obj = new NumArray(nums); * int param_1 = obj.sumRange(i,j); */
[LC] 303. Range Sum Query - Immutable
标签：ant integer called class and ret man dice ted
原文地址：https://www.cnblogs.com/xuanlu/p/12008635.html
