Can you solve this real interview question? Range Sum Query 2D - Immutable - Given a 2D matrix matrix, handle multiple queries of the following type: * Calculate the sum of the elements of matrix inside the rectangle defined by its upper left corner (r
状态:我们声明一个同给定数组一样大小的二维矩阵self.sum,self.sum的每个位置的值self.sum[i][j]表示给定矩阵从matrix[0][0]到matrix[i][j]构成的矩阵的和. 转移方程:我们用temp记录第matirx第i行的前j个数的和,则self.sum[i][j] = temp+self.sum[i-1][j] 答案,area3 - area1 - area2.如下...
Range Sum Query 2D - Immutable 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 (...
LeetCode-Range Sum Query 2D - Immutable Given a 2D matrixmatrix, 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 ...
There are many calls to sumRegion function. You may assume that row1 ≤ row2 and col1 ≤ col2. 题意很简单,做法也很简单,把上一道题leetcode 303. Range Sum Query - Immutable 字串求和 + DP 做一下扩展即可。 代码如下: /* * 就是面积的迭代计算 ...
LeetCode "Range Sum Query 2D - Immutable",Yestheaccu*isnotnecessary:)classNumMatrix{vector>dp;public:NumMatrix(vector>&matrix){inth=matrix.size();if(!h)ret...
There are many calls tosumRegionfunction. You may assume thatrow1 ≤row2 andcol1 ≤col2. 这道题让我们求一个二维区域和的检索,是之前那道题Range Sum Query - Immutable 区域和检索的延伸。有了之前那道题的基础,我们知道这道题其实也是换汤不换药,还是要建立一个累计区域和的数组,然后根据边界值的加...
LeetCode-3/C++/range-sum-query-2d-immutable.cpp Go to file 41 lines (35 sloc) 1.08 KB Raw Blame // Time: ctor: O(m * n), // lookup: O(1) // Space: O(m * n) class NumMatrix { public: NumMatrix(vector<vector<int>> &matrix) { if (matrix.empty()) { return; } const...
Golang中如何实现Range Sum Query - Immutable功能? 在Leetcode 303题中,Golang的解法有哪些优化技巧? Golang实现Range Sum Query - Immutable时,时间复杂度是多少? 版权声明:原创勿转 https://cloud.tencent.com/developer/article/1412946 思路 保存一个slice code 代码语言:javascript 代码运行次数:0 运行 AI...
[LeetCode] 304. Range Sum Query 2D - Immutable 2019-12-10 11:35 − Medium Given a 2D matrix matrix, find the sum of the elements inside the rectangle defined by its upper left corner (row1, col1) and lower ri... 程嘿嘿 0 174 ...