pwc281 solution in go

2 files changed, 169 insertions, 0 deletions

diff --git a/challenge-281/pokgopun/go/ch-1.go b/challenge-281/pokgopun/go/ch-1.go
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+++ b/challenge-281/pokgopun/go/ch-1.go
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+//# https://theweeklychallenge.org/blog/perl-weekly-challenge-281/
+/*#
+
+Task 1: Check Color
+
+Submitted by: [47]Mohammad Sajid Anwar
+     __________________________________________________________________
+
+   You are given coordinates, a string that represents the coordinates of
+   a square of the chessboard as shown below:
+
+   Week_281_Task_1
+
+   Write a script to return true if the square is light, and false if the
+   square is dark.
+
+Example 1
+
+Input: $coordinates = "d3"
+Output: true
+
+Example 2
+
+Input: $coordinates = "g5"
+Output: false
+
+Example 3
+
+Input: $coordinates = "e6"
+Output: true
+
+Task 2: Knight’s Move
+#*/
+//# solution by pokgopun@gmail.com
+
+package main
+
+import (
+	"io"
+	"os"
+
+	"github.com/google/go-cmp/cmp"
+)
+
+func checkColor(str string) bool {
+	return ((str[0] % 2) + (str[1] % 2)) == 1
+}
+
+func main() {
+	for _, data := range []struct {
+		input  string
+		output bool
+	}{
+		{"d3", true},
+		{"g5", false},
+		{"e6", true},
+	} {
+		io.WriteString(os.Stdout, cmp.Diff(checkColor(data.input), data.output)) // blank if ok, otherwise show the difference
+	}
+}
diff --git a/challenge-281/pokgopun/go/ch-2.go b/challenge-281/pokgopun/go/ch-2.go
new file mode 100644
index 0000000000..9f4f229646
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+++ b/challenge-281/pokgopun/go/ch-2.go
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+//# https://theweeklychallenge.org/blog/perl-weekly-challenge-281/
+/*#
+
+Task 2: Knight’s Move
+
+Submitted by: [48]Peter Campbell Smith
+     __________________________________________________________________
+
+   A Knight in chess can move from its current position to any square two
+   rows or columns plus one column or row away. So in the diagram below,
+   if it starts a S, it can move to any of the squares marked E.
+
+   Write a script which takes a starting position and an ending position
+   and calculates the least number of moves required.
+
+   Week_281_Task_2
+
+Example 1
+
+Input: $start = 'g2', $end = 'a8'
+Ouput: 4
+
+g2 -> e3 -> d5 -> c7 -> a8
+
+Example 2
+
+Input: $start = 'g2', $end = 'h2'
+Ouput: 3
+
+g2 -> e3 -> f1 -> h2
+     __________________________________________________________________
+
+   Last date to submit the solution 23:59 (UK Time) Sunday 11th August
+   2024.
+     __________________________________________________________________
+
+SO WHAT DO YOU THINK ?
+#*/
+//# solution by pokgopun@gmail.com
+// https://afteracademy.com/blog/knight-on-chessboard/#:~:text=Solution,the%20shape%20of%20an%20L).
+
+package main
+
+import (
+	"io"
+	"os"
+
+	"github.com/google/go-cmp/cmp"
+)
+
+type position struct {
+	x, y int
+}
+
+func newPosition(label string) position {
+	return position{int(label[0]) - 96, int(label[1]) - 48}
+}
+
+func (pt position) String() string {
+	return string([]byte{byte(pt.x) + 96, byte(pt.y) + 48})
+}
+
+type data struct {
+	count   int
+	visited bool
+}
+
+type board [8][8]data
+
+func (bd board) contains(p position) bool {
+	return p.x >= 1 && p.x <= 8 && p.y >= 1 && p.y <= 8
+}
+
+func knightMove(start, end string) int {
+	var bd board
+	p0 := newPosition(start)
+	p1 := newPosition(end)
+	queue := []position{p0}
+	bd[p0.x-1][p0.y-1] = data{visited: true}
+	dx := [8]int{-2, -1, 1, 2, -2, -1, 1, 2}
+	dy := [8]int{-1, -2, -2, -1, 1, 2, 2, 1}
+	for len(queue) > 0 {
+		p := queue[0]
+		queue = queue[1:]
+		if p.x == p1.x && p.y == p1.y {
+			return bd[p.x-1][p.y-1].count
+		}
+		for i := 0; i < 8; i++ {
+			pn := position{p.x + dx[i], p.y + dy[i]}
+			if bd.contains(pn) && !bd[pn.x-1][pn.y-1].visited {
+				bd[pn.x-1][pn.y-1] = data{visited: true, count: bd[p.x-1][p.y-1].count + 1}
+				queue = append(queue, pn)
+			}
+		}
+	}
+	return -1
+}
+
+func main() {
+	for _, data := range []struct {
+		start, end string
+		count      int
+	}{
+		{"g2", "a8", 4},
+		{"g2", "h2", 3},
+	} {
+		io.WriteString(os.Stdout, cmp.Diff(knightMove(data.start, data.end), data.count)) // blank if ok, otherwise show the difference
+	}
+}