sudoku-funpark/solver/blocks.go

package solver

import (
	"encoding/csv"
	"io"
	"log"
	"os"
	"strconv"
)

func (solver *Solver) load_blocks() {
	var blocks []int

	file, err := os.Open("blocks.csv")
	if err != nil {
		panic(err)
	}
	defer file.Close()

	r := csv.NewReader(file)
	for {
		record, err := r.Read()
		if err == io.EOF {
			break
		}
		if err != nil {
			log.Fatal(err)
		}

		block, _ := strconv.Atoi(record[0])
		blocks = append(blocks, block)
	}
	solver.blocks = blocks
}

func (solver *Solver) generate_blocks() []int {

	var blocks []int
	decvals := [9]int{49, 50, 51, 52, 53, 54, 55, 56, 57}

	for counter := 123456789; counter <= 987654321; counter++ {

		// Convert number to string ([]byte)
		digits := strconv.Itoa(counter)

		// Check if every number is only represented only once
		var valid bool
		valid = true
		for decval := range decvals {
			var count int
			for digit := range digits {
				if digits[digit] == byte(decvals[decval]) {
					count = count + 1
				}
			}

			if count != 1 {
				valid = false
			}
		}

		if valid {
			blocks = append(blocks, counter)
		}
	}

	return blocks

}