[With Golang Brush Leetcode 7] 566. Reshape the Matrix

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Topic

In MATLAB, there are 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 the positive integers r and C representing the row Numbe R and column number of the wanted reshaped matrix, respectively.

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

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

Example 1:

Input:
Nums =
[[+],
[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, and the fill it row by row by using the previous list.

Example 2:

Input:
Nums =
[[+],
[3,4]]
R = 2, c = 4
Output:
[[+],
[3,4]]

explanation:
There is no-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 is all positive.

Main topic:

Given a two-dimensional matrix nums, it is transformed into a new matrix of row C columns of R. If the conversion cannot be completed, return to the original matrix.

Attention:

The height and width range of a given matrix [1, 100]
Both R and C are positive numbers.

Thinking of solving problems

1. Origin_r * Origin_c matrix reshape for RC, need to satisfy:
   Origin_r * Origin_c=rC
2. Relationship of element position
   If the matrix is expanded horizontally into a one-dimensional array, the number of elements is N=origin_r * Origin_c
   In the position of the element in the one-dimensional array I:
   Original matrix position [I/origin_c,i%origin_c]
   New matrix position [i/c,i%c]

Code

Reshapematrix.go

package _566_Reshape_Matriximport "fmt"func MatrixReshape(nums [][]int, r int, c int) [][]int {    var chanInt chan int    chanInt = make(chan int)    var length int    go func(len *int) {        for _, v1 := range nums {            for _, v := range v1 {                (*len)++                fmt.Printf("len1:%+v\n", length)                chanInt <- v            }        }        for {            chanInt <- 0        }    }(&length)    var ret [][]int    for i := 0; i < r; i++ {        var lineRet []int        for j := 0; j < c; j++ {            v := <- chanInt            lineRet = append(lineRet, v)        }        ret = append(ret, lineRet)    }    fmt.Printf("len2:%+v\n", length)    fmt.Printf("ret:%+v\n", ret)    if r * c != length {        return nums    }    return ret}

Test

Reshapematrix_test.go

The 
  package _566_reshape_matriximport "Testing" func Testmatrixreshape (t *testing. T) {input: = [][]int{{1, 2}, {3, 4},} RET: = Matrixreshape (Input, 1, 4) t.logf ("%+v", ret)}