LeetCode：区域和检索【303】

【LeetCode：区域和检索【303】】的更多相关文章

LeetCode：区域和检索【303】

LeetCode:区域和检索[303] 题目描述给定一个整数数组 nums,求出数组从索引 i 到 j (i ≤ j) 范围内元素的总和,包含 i, j 两点. 示例: 给定 nums = [-2, 0, 3, -5, 2, -1],求和函数为 sumRange() sumRange(0, 2) -> 1 sumRange(2, 5) -> -1 sumRange(0, 5) -> -3 说明: 你可以假设数组不可变. 会多次调用 sumRange 方法. 题目分析 sums[i…

[LeetCode] 303. Range Sum Query - Immutable 区域和检索 - 不可变

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: You may assume that the array do…

Java实现 LeetCode 303 区域和检索 - 数组不可变

303. 区域和检索 - 数组不可变给定一个整数数组 nums,求出数组从索引 i 到 j (i ≤ j) 范围内元素的总和,包含 i, j 两点. 示例: 给定 nums = [-2, 0, 3, -5, 2, -1],求和函数为 sumRange() sumRange(0, 2) -> 1 sumRange(2, 5) -> -1 sumRange(0, 5) -> -3 说明: 你可以假设数组不可变. 会多次调用 sumRange 方法. class NumArray { pri…

[Leetcode]303.区域和检索&&304.二维区域和检索

题目 1.区域和检索: 简单题,前缀和方法乍一看就觉得应该用前缀和来做,一个数组多次查询. 实现方法: 新建一个private数组prefix_sum[i],用来存储nums前i个数组的和, 需要找区间和的时候直接通过prefix_sum[j]-prefix[i-1]即可得到从[i,j]区间的和,当i是0的时候需要特殊处理以防数组越界. class NumArray { public: NumArray(vector<int> nums) { prefix_sum.reserve(nums.…

[LeetCode] 304. Range Sum Query 2D - Immutable 二维区域和检索 - 不可变

Given a 2D matrix matrix, find the sum of the elements inside the rectangle defined by its upper left corner (row1, col1) and lower right corner (row2, col2). The above rectangle (with the red border) is defined by (row1, col1) = (2, 1) and (row2, co…

[LeetCode] Range Sum Query 2D - Mutable 二维区域和检索 - 可变

Given a 2D matrix matrix, find the sum of the elements inside the rectangle defined by its upper left corner (row1, col1) and lower right corner (row2, col2). The above rectangle (with the red border) is defined by (row1, col1) = (2, 1) and (row2, co…

[LeetCode] Range Sum Query 2D - Immutable 二维区域和检索 - 不可变

Given a 2D matrix matrix, find the sum of the elements inside the rectangle defined by its upper left corner (row1, col1) and lower right corner (row2, col2). The above rectangle (with the red border) is defined by (row1, col1) = (2, 1) and (row2, co…