Range Sum Query 2D - Immutable
来源:互联网 发布:mac用什么浏览器比较好 编辑:程序博客网 时间:2024/05/17 02:41
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, col2) = (4, 3), which contains sum = 8.
Example:
Given matrix = [ [3, 0, 1, 4, 2], [5, 6, 3, 2, 1], [1, 2, 0, 1, 5], [4, 1, 0, 1, 7], [1, 0, 3, 0, 5]]sumRegion(2, 1, 4, 3) -> 8sumRegion(1, 1, 2, 2) -> 11sumRegion(1, 2, 2, 4) -> 12
Note:
- You may assume that the matrix does not change.
- There are many calls to sumRegion function.
- You may assume that row1 ≤ row2 and col1 ≤ col2.
class NumMatrix {public: NumMatrix(vector<vector<int>> &matrix) { int sum = 0; for (int i = 0; i < matrix.size(); i++) { vector<int> row; sum = 0; for (int j = 0; j < matrix[i].size(); j++) { sum += matrix[i][j]; if (i == 0) { row.push_back(sum); } else { row.push_back(sum + this->matrix[i - 1][j]); } } this->matrix.push_back(row); } } int sumRegion(int row1, int col1, int row2, int col2) { int res = 0; if (row1 != 0 && col1 != 0) { res = matrix[row2][col2] - matrix[row1 - 1][col2] - matrix[row2][col1 - 1] + matrix[row1 - 1][col1 - 1]; } else if (row1 == 0 && col1 != 0) { res = matrix[row2][col2] - matrix[row2][col1 - 1]; } else if (row1 != 0 && col1 == 0) { res = matrix[row2][col2] - matrix[row1 - 1][col2]; } else { res = matrix[row2][col2]; } return res; }private: vector<vector<int>> matrix;};
0 0
- Range Sum Query 2D - Immutable
- Range Sum Query 2D - Immutable
- [Leetcode]Range Sum Query 2D - Immutable
- Range Sum Query 2D - Immutable
- Leetcode Range Sum Query 2D - Immutable
- LeetCode Range Sum Query 2D - Immutable
- [Leetcode]Range Sum Query 2D - Immutable
- Leetcode194: Range Sum Query 2D - Immutable
- Leetcode Range Sum Query 2D - Immutable
- Leetcode: Range Sum Query 2D - Immutable
- Range Sum Query 2D - Immutable
- Leetcode: Range Sum Query 2D - Immutable
- LeetCode304. Range Sum Query 2D - Immutable
- 304. Range Sum Query 2D - Immutable
- leetcode:Range Sum Query 2D - Immutable
- 304. Range Sum Query 2D - Immutable
- LeetCode|Range Sum Query 2D - Immutable
- 304. Range Sum Query 2D - Immutable
- android 学习笔记之AndBase框架学习(六) PullToRefrech 下拉刷新的实现
- UI调试工具Reveal的简单用法,下载地址
- IOS小型计算器实例代码
- 关于建立远程连接HttpRequest 遇到的问题
- spring AOP(动态代理)解析
- Range Sum Query 2D - Immutable
- 写给自己------21次的坚持
- Bug猜想(二)
- HDU 2767:Proving Equivalences【强连通】
- UIApplication详解
- Java动态代理详解
- UIVIew详解
- 十进制中正整数N中1的个数
- c语言之多级指针理解二