标签：nbsp 大小 output matrix int vector span 矩阵 serve
题目描述：
Given a matrix A, return the transpose of A.
The transpose of a matrix is the matrix flipped over it‘s main diagonal, switching the row and column indices of the matrix.
Example 1:
Input: [[1,2,3],[4,5,6],[7,8,9]]
Output: [[1,4,7],[2,5,8],[3,6,9]]
Example 2:
Input: [[1,2,3],[4,5,6]]
Output: [[1,4],[2,5],[3,6]]
Note:
1 <= A.length <= 10001 <= A[0].length <= 1000解题思路：
暴力遍历原来矩阵的每个元素，放到输出矩阵的对应位置。
由于veector的内存分配机制，由于已知输出矩阵的大小，所以在每个vector定义时指定空间大小会节省运行时间。
代码：
1 class Solution { 2 public: 3 vector<vector<int>> transpose(vector<vector<int>>& A) { 4 vector<vector<int> > res; 5 res.reserve(A[0].size()); 6 for (int i = 0; i < A[0].size(); ++i) { 7 vector<int> tmp; 8 tmp.reserve(A.size()); 9 for (int j = 0; j < A.size(); ++j) { 10 tmp.push_back(A[j][i]); 11 } 12 res.push_back(tmp); 13 } 14 return res; 15 } 16 };
标签：nbsp 大小 output matrix int vector span 矩阵 serve
原文地址：https://www.cnblogs.com/gsz-/p/9403349.html
