In this program, I'm trying to calculate the shortest path between any two squares on chess board according to the moves of the knight, I checked few websites they say something about finding out the length, I ddint quiet understand how to work with.I'm encountering a error saying "panic:index out of range" Can anybody help me out..!! please
package main
import (
"bufio"
"fmt"
"os"
"sort"
"strings"
)
var heightcurrstack int
var currentSource string
var currentDest string
var currentDestn int
var PosMoves [8]int
func main() {
file, err := os.Open("chessin.txt")
if err != nil {
fmt.Println(err)
}
defer file.Close()
scanner := bufio.NewScanner(file)
for scanner.Scan() {
strs := strings.Split(scanner.Text(), ",")
currentSource = strs[0]
currentDest = strs[1]
IsValid(currentSource)
toNumber(currentSource)
IsValid(currentDest)
currentDestn = toNumber(currentDest)
}
}
func IsValid(b string) bool {
if b[0] <= 'H' && b[0] >= 'A' && b[1] <= '8' && b[1] >= '1' {
return true
}
return false
}
func toNumber(s string) int {
var Number int
if len(s) != 2 {
fmt.Println("Invalid Input", s, ".")
}
Number = int(s[0]-'A')*8 + int(s[1]-'0')
return Number
}
func ToString(n int) string {
n--
return string((n/8)+65) + string((n%8)+49)
}
func PossibleMoves(n int) [8]int {
a := ToString(n)
isval := IsValid(a)
if isval == true {
if IsValid(string(a[0]+1) + string(a[1]+2)) {
PosMoves[0] = toNumber(string(a[0]+1) + string(a[1]+2))
}
if IsValid(string(a[0]+1) + string(a[1]-2)) {
PosMoves[1] = toNumber(string(a[0]+1) + string(a[1]-2))
}
if IsValid(string(a[0]-1) + string(a[1]+2)) {
PosMoves[2] = toNumber(string(a[0]-1) + string(a[1]+2))
}
if IsValid(string(a[0]-1) + string(a[1]-2)) {
PosMoves[3] = toNumber(string(a[0]-1) + string(a[1]-2))
}
if IsValid(string(a[0]+2) + string(a[1]+1)) {
PosMoves[4] = toNumber(string(a[0]+2) + string(a[1]+1))
}
if IsValid(string(a[0]+2) + string(a[1]-1)) {
PosMoves[5] = toNumber(string(a[0]+2) + string(a[1]-1))
}
if IsValid(string(a[0]-2) + string(a[1]+1)) {
PosMoves[6] = toNumber(string(a[0]-2) + string(a[1]+1))
}
if IsValid(string(a[0]-2) + string(a[1]-1)) {
PosMoves[7] = toNumber(string(a[0]-2) + string(a[1]-1))
}
}
sort.Sort(sort.Reverse(sort.IntSlice(PosMoves[0:8])))
return PosMoves
}
var visithistory [64]bool
func IsvisitedNode(currentSource int) bool {
visithistory[currentSource] = true
if visithistory[currentSource] == true {
return false
}
return true
}
type stack []int
func (s stack) Push(currentSource int) stack {
return append(s, currentSource)
}
func (s stack) Pop() ([]int) {
heightcurrstack := len(s)
return s[0:heightcurrstack]
}
func dfstraversal(currentSource int) {
var currentchildren [8]int
copy(PosMoves[:], currentchildren[:])
s := make(stack, 0)
if IsvisitedNode(currentSource) == true {
var j int = 0
for j < len(currentchildren) {
currentchildren[j+1] = currentSource
}
} else if IsvisitedNode(currentSource) == false { //condition 1:previously not visited
if heightcurrstack > 6 { //condition 2: if the number of moves are more than 6
tracesuccessfulpath()
}
if currentSource == currentDestn { //condition 3 : if the destination posititon is found
tracesuccessfulpath()
}
s = s.Push(currentSource)
s = s.Push(currentchildren[0])
currentchildren[0] = currentSource
if currentSource == currentDestn {
tracesuccessfulpath()
}
}
PossibleMoves(currentSource)
dfstraversal(currentSource)
}
func tracesuccessfulpath() {
s := make(stack, 0)
s.Pop()
var Path []string
for _,x := range s {
Path := append(Path, ToString(x))
fmt.Println(Path)
}
}
