zoukankan      html  css  js  c++  java
  • 566. Reshape the Matrix

    In MATLAB, there is a very useful function called 'reshape', which can reshape a matrix into a new one with different size but keep its original data.

    You're given a matrix represented by a two-dimensional array, and two positive integers r and c representing the row number and column number of the wanted reshaped matrix, respectively.

    The reshaped matrix need to be filled with all the elements of the original matrix in the same row-traversing order as they were.

    If the 'reshape' operation with given parameters is possible and legal, output the new reshaped matrix; Otherwise, output the original matrix.

    Example 1:

    Input: 
    nums = 
    [[1,2],
     [3,4]]
    r = 1, c = 4
    Output: 
    [[1,2,3,4]]
    Explanation:
    The row-traversing of nums is [1,2,3,4]. The new reshaped matrix is a 1 * 4 matrix, fill it row by row by using the previous list.

    Example 2:

    Input: 
    nums = 
    [[1,2],
     [3,4]]
    r = 2, c = 4
    Output: 
    [[1,2],
     [3,4]]
    Explanation:
    There is no way to reshape a 2 * 2 matrix to a 2 * 4 matrix. So output the original matrix.

    Note:

    1. The height and width of the given matrix is in range [1, 100].
    2. The given r and c are all positive.

    解题思路:
    这里row-traversing不是很清楚是什么意思,好吧,一试发现就是按照行的顺序排列过去。

    class Solution {
    public:
    vector<vector<int>> matrixReshape(vector<vector<int>>& nums, int r, int c) {

    if(nums.size() == 0) return nums;
    if(nums[0].size()*nums.size() != (r * c)) return nums; // not equal the condition

    vector<vector<int>> new_nums;
    vector<int> row;
    int cur_i=0,cur_j=0;

    for(int i=0;i<r;i++){
    row.clear();
    for(int j=0;j<c;j++){
    row.push_back(nums[cur_i][cur_j++]);
    if(cur_j>=nums[0].size()) {cur_j=0;cur_i++;}

    }
    new_nums.push_back(row);
    }

    return new_nums;


    }
    };

  • 相关阅读:
    微信小程序如何获取openid
    js经典试题之常用的方法
    js经典试题之运算符的优先级
    js如何使浏览器允许脚本异步加载
    es6从零学习(五):Module的语法
    es6从零学习(四):Class的继承
    js如何处理字符串中带有↵字符
    Zuul中聚合Swagger的坑
    阿里Sentinel支持Spring Cloud Gateway啦
    Spring Boot中的Mongodb多数据源扩展
  • 原文地址:https://www.cnblogs.com/liangyc/p/8782725.html
Copyright © 2011-2022 走看看