對稀疏CSC矩陣Golang的行進行排序

我正在嘗試分析稀疏矩陣。面臨按原始矩陣中元素的升序對行進行排序的任務。

但我不明白如何在不損壞空元素的情況下做到這一點。

我試圖將 sum 陣列的元素系結到行并以某種方式移動它們。但一些元素已從 CSC 結構中洗掉。

可能有必要更改 li/lj 陣列本身，但我沒有足夠的數學知識。更準確地說，我不明白如何跟蹤何時應該重新排列元素，除非在結構中明確指定了其他元素（零）。

package main

import (
    "fmt"
)

type CSC struct {
    a, lj, li []int
}

func getEl(i, j int, el *CSC) int {
    for k := el.lj[j]; k < el.lj[j 1]; k   {
        if el.li[k] == i {
            return el.a[k]
        }
    }
    return 0
}

func maxSliceEl(lj []int) int {
    max := 0

    for _, v := range lj {
        if v > max {
            max = v
        }
    }
    return max
}

func main() {
    ma := CSC{
        a:  []int{8, 2, 5, 7, 1, 9, 2},
        li: []int{0, 0, 1, 4, 4, 6, 4},
        lj: []int{0, 1, 1, 4, 6, 7},
    }

    n := len(ma.lj)   1
    m := maxSliceEl(ma.li) - 1
    fmt.Printf("Col: %v, Row: %v\n", n, m)

    maxStr := []int{}

    fmt.Println("Initial matrix:")
    for i := 0; i < n; i   {

        sumStrEl := 0
        for j := 0; j < m; j   {
            fmt.Print(getEl(i, j, &ma), " ")
            sumStrEl  = getEl(i, j, &ma)
        }

        maxStr = append(maxStr, sumStrEl)
        fmt.Println("|sumStrEl: ", sumStrEl)
    }

}

uj5u.com熱心網友回復：

我通過將結構作為解決方案找到了解決問題的方法：元素之和 它們的索引。結果證明解決方案比預期的要簡單，只是缺少解決稀疏矩陣的實踐。sum 的位置 [i] 必須作為第一個引數傳遞給 getEl 函式。

package main

import (
    "fmt"
    "sort"
)

// Creating a CSC (CCS) matrix structure
type CSC struct {
    // Array of values, column indexes, row indexing
    a, lj, li []int
}

// Getting access to the element
func getEl(i, j int, el *CSC) int {
    for k := el.lj[j]; k < el.lj[j 1]; k   {
        // If the element string is equal to the string of the searched element, then the element is found
        if el.li[k] == i {
            return el.a[k]
        }
    }
    // Otherwise, we will return 0. It will be entered into the matrix
    return 0
}

func maxSliceEl(lj []int) int {
    max := 0

    for _, v := range lj {
        if v > max {
            max = v
        }
    }
    return max
}

type strInfo struct {
    summa int
    pos   int
}

func main() {
    // Set the CSC matrix
    ma := CSC{
        a:  []int{8, 2, 5, 7, 1, 9, 2},
        li: []int{0, 0, 1, 4, 4, 6, 4},
        lj: []int{0, 1, 1, 4, 6, 7},
    }

    // Define the number of columns
    n := len(ma.lj)   1
    // Define the number of rows
    m := maxSliceEl(ma.li) - 1
    fmt.Printf("Cols: %v, Rows: %v\n", m, n)

    // Set a variable with a structure type for calculating 
    // the amount in a row and indexing each element in it
    var stringsInfo []strInfo

    fmt.Println("Initial matrix:")
    for i := 0; i < n; i   {
        sumStrEl := 0

        for j := 0; j < m; j   {
            sumStrEl  = getEl(i, j, &ma)
            fmt.Print(getEl(i, j, &ma), " ")
        }
        fmt.Println("|", sumStrEl)

        // Adding a cell with the sum and index to the slice
        var strI strInfo
        strI.summa = sumStrEl
        strI.pos = i
        stringsInfo = append(stringsInfo, strI)
    }

    fmt.Println("stringsInfo: ", stringsInfo)

    // Sorting the stringsInfo slice in ascending order of the sum elements
    sort.Slice(stringsInfo, func(i, j int) (less bool) {
        return stringsInfo[i].summa < stringsInfo[j].summa
    })

    fmt.Println("stringsInfo: ", stringsInfo)

    fmt.Println("Sorted matrix:")
    for i := range stringsInfo {
        for j := 0; j < m; j   {
            // Output the matrix by idnex stringsInfo[i].pos
            fmt.Print(getEl(stringsInfo[i].pos, j, &ma), " ")
        }
        fmt.Println("|", stringsInfo[i].summa)
    }
}

標籤：去矩阵稀疏矩阵csc

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