题解 | 矩阵乘法

package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
	"strings"
)

func strToInt(str string) int {
	v, _ := strconv.Atoi(str)
	return v
}

func strArrToIntArr(strs []string) []int {
	result := []int{}

	for _, str := range strs {
		result = append(result, strToInt(str))
	}

	return result
}

func IntArrToStrArrTo(ints []int) []string {
	result := []string{}

	for _, i := range ints {
		result = append(result, fmt.Sprintf("%v", i))
	}

	return result
}

func main() {
	var x, y, z int
	_, _ = fmt.Scan(&x)
	_, _ = fmt.Scan(&y)
	_, _ = fmt.Scan(&z)

	// fmt.Printf("x,y,z: %v,%v,%v\n", x, y, z)
	scanner := bufio.NewScanner(os.Stdin)
	xArr := [][]int{}
	for i := 0; i < x; i++ {
		scanner.Scan()
		xRow := scanner.Text()
		xRowVals := strings.Split(xRow, " ")
		if len(xRow) == 0 {
			continue
		}
		if len(xRowVals) != y {
			fmt.Printf("len not y, %#v, x,y,z: %v,%v,%v", xRowVals, x, y, z)
			return
		}

		xArr = append(xArr, strArrToIntArr(xRowVals))
	}

	// fmt.Printf("xArr %#v\n", xArr)

	yArr := [][]int{}
	for i := 0; i < y; i++ {
		scanner.Scan()
		row := scanner.Text()
		rowVals := strings.Split(row, " ")
		if len(rowVals) != z {
			fmt.Printf("len not z, %#v, row: %v, x,y,z: %v,%v,%v", rowVals, row, x, y, z)
			return
		}

		yArr = append(yArr, strArrToIntArr(rowVals))
	}

	// fmt.Printf("yArr %#v\n", yArr)

	// c:
	cArr := [][]int{}
	for xi := 0; xi < x; xi++ {
		cRow := []int{}
		for zi := 0; zi < z; zi++ {
			cXY := 0
			for yi := 0; yi < y; yi++ {
				cXY += (xArr[xi][yi] * yArr[yi][zi])
			}

			cRow = append(cRow, cXY)
		}

		cArr = append(cArr, cRow)
	}

	for _, cRow := range cArr {
		fmt.Println(strings.Join(IntArrToStrArrTo(cRow), " "))
	}
}