🔥 Join LeetCode to Code! View your Submission records hereRegister or Sign In C++ Auto 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16class NumMatrix { public: NumMatrix(vector<vector<int>>& matrix) {}int sumRegion(int row1, int col1, int row2, int col2) {}...
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 ...
1classNumMatrix {2public:3NumMatrix(vector<vector<int>> &matrix){4if(!matrix.size() || !matrix[0].size())5return;6sum = vector<vector<int>>(matrix.size(), vector<int>(matrix[0].size(),0));7for(inti =0; i < matrix.size(); ++i){8for(intj =0; j < matrix[0].size();...
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 * DP的一个简单应用 * */ class NumMatr...
LeetCode "Range Sum Query 2D - Immutable",Yestheaccu*isnotnecessary:)classNumMatrix{vector>dp;public:NumMatrix(vector>&matrix){inth=matrix.size();if(!h)ret...
Val { ans += rangeSumBST(root.Left, low, high) } // 如果 root 结点值小于 high ,则其右子树可能存在需要统计的结点,递归处理右子树 if root.Val < high { ans += rangeSumBST(root.Right, low, high) } return ans } 题目链接: Range Sum of BST: leetcode.com/problems/r 二叉搜索树的...
https://leetcode.com/problems/range-sum-query-2d-mutable/discuss/75870/Java-2D-Binary-Indexed-Tree-Solution-clean-and-short-17ms class NumMatrix { int N, M; int[][] bitTree; int[][] matrix; public NumMatrix(int[][] matrix) { if (matrix == null || matrix.length == 0 || matri...
另外一种思路,在数组最前面加上一个0。这样一来,就有sumRange(i, j) = sum[j + 1] - sum[i],避免了可能的越界。 Code //Runtime: 169msclass NumArray{public:vector<int>sum;NumArray(vector<int>nums){inttmp=0;sum.push_back(tmp);intnumSize=nums.size();for(inti=0;i<numSize;i++){...
[leetcode]304. Range Sum Query 2D - Immutable 题目链接:https://leetcode.com/problems/range-sum-query-2d-immutable/#/description Given a 2D matrix matrix, find the sum of the elements inside the rectangle defined by its upper left corner (row1,&n......
int sumRegion(int row1, int col1, int row2, int col2) { return sums_[row2 + 1][col2 + 1] - sums_[row2 + 1][col1] - sums_[row1][col2 + 1] + sums_[row1][col1]; } private: vector<vector<int>> sums_; }; // Your NumMatrix object will be instantiated and call...