pwc246 solution in go

2 files changed, 226 insertions, 0 deletions

diff --git a/challenge-246/pokgopun/go/ch-1.go b/challenge-246/pokgopun/go/ch-1.go
new file mode 100644
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+++ b/challenge-246/pokgopun/go/ch-1.go
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+//# https://theweeklychallenge.org/blog/perl-weekly-challenge-246/
+/*#
+
+Task 1: 6 out of 49
+
+Submitted by: [46]Andreas Voegele
+     __________________________________________________________________
+
+   6 out of 49 is a German lottery.
+
+   Write a script that outputs six unique random integers from the range 1
+   to 49.
+
+Output
+
+3
+10
+11
+22
+38
+49
+
+Task 2: Linear Recurrence of Second Order
+#*/
+//# solution by pokgopun@gmail.com
+
+package main
+
+import (
+	"fmt"
+	"math/rand"
+	"time"
+)
+
+type gmLot struct {
+	rg  *rand.Rand
+	val [6]uint8
+}
+
+func newGmLot() gmLot {
+	gl := gmLot{rg: rand.New(rand.NewSource(time.Now().UnixNano()))}
+	gl.update()
+	return gl
+}
+
+func (gl gmLot) String() string {
+	return fmt.Sprint(gl.val)
+}
+
+func (gl *gmLot) update() {
+	i := 0
+	for _, v := range gl.rg.Perm(50)[:7] {
+		if v != 0 {
+			gl.val[i] = uint8(v)
+			i++
+		}
+		if i == 6 {
+			break
+		}
+	}
+}
+
+func (gl gmLot) isInRange() bool {
+	for _, v := range gl.val {
+		if v < 1 || v > 49 {
+			return false
+		}
+	}
+	return true
+}
+
+func (gl gmLot) isUnique() bool {
+	m := make(map[uint8]bool)
+	for _, v := range gl.val {
+		if m[v] {
+			return false
+		}
+		m[v] = true
+	}
+	return true
+}
+
+func (gl *gmLot) hasNoDupAfterN(n uint) bool {
+	m := make(map[[6]uint8]bool)
+	for i := uint(0); i < n; i++ {
+		if m[gl.val] {
+			//fmt.Println(m)
+			return false
+		}
+		m[gl.val] = true
+		//if i < n/2 {
+		gl.update()
+		//fmt.Println(gl)
+		//}
+	}
+	//fmt.Println(m)
+	return true
+}
+
+func main() {
+	gl := newGmLot()
+	fmt.Println(gl.isInRange(), gl.isUnique(), gl.hasNoDupAfterN(100), gl)
+}
diff --git a/challenge-246/pokgopun/go/ch-2.go b/challenge-246/pokgopun/go/ch-2.go
new file mode 100644
index 0000000000..28a2f986fa
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+++ b/challenge-246/pokgopun/go/ch-2.go
@@ -0,0 +1,123 @@
+//# https://theweeklychallenge.org/blog/perl-weekly-challenge-246/
+/*#
+
+Task 2: Linear Recurrence of Second Order
+
+Submitted by: [47]Jorg Sommrey
+     __________________________________________________________________
+
+   You are given an array @a of five integers.
+
+   Write a script to decide whether the given integers form a linear
+   recurrence of second order with integer factors.
+
+   A linear recurrence of second order has the form
+a[n] = p * a[n-2] + q * a[n-1] with n > 1
+
+where p and q must be integers.
+
+Example 1
+
+Input: @a = (1, 1, 2, 3, 5)
+Output: true
+
+@a is the initial part of the Fibonacci sequence a[n] = a[n-2] + a[n-1]
+with a[0] = 1 and a[1] = 1.
+
+Example 2
+
+Input: @a = (4, 2, 4, 5, 7)
+Output: false
+
+a[1] and a[2] are even. Any linear combination of two even numbers with integer
+factors is even, too.
+Because a[3] is odd, the given numbers cannot form a linear recurrence of second
+ order with integer factors.
+
+Example 3
+
+Input: @a = (4, 1, 2, -3, 8)
+Output: true
+
+a[n] = a[n-2] - 2 * a[n-1]
+     __________________________________________________________________
+
+   Last date to submit the solution 23:59 (UK Time) Sunday 10th December
+   2023.
+     __________________________________________________________________
+
+SO WHAT DO YOU THINK ?
+#*/
+//# solution by pokgopun@gmail.com
+
+package main
+
+import "fmt"
+
+type equation struct {
+	a, b, c int // a*p + b*q = c
+}
+
+type answer struct {
+	isValid bool // true if both p and q are ints
+	p, q    int  // Only correct if isValid==true
+}
+
+func (eqt equation) solve(aeqt equation) answer {
+	// q = dvd / dvs
+	dvd, dvs := aeqt.a*eqt.c-eqt.a*aeqt.c, aeqt.a*eqt.b-aeqt.b*eqt.a
+	if dvd%dvs != 0 {
+		return answer{false, 0, 0}
+	}
+	q := dvd / dvs
+	//fmt.Println(eqt, aeqt, dvd, dvs)
+	// p = dvd / dvs
+	dvd, dvs = eqt.c-eqt.b*q, eqt.a
+	if dvd%dvs != 0 {
+		return answer{false, 0, 0}
+	}
+	p := dvd / dvs
+	return answer{true, p, q}
+}
+
+type equations []equation
+
+func newEquations(ints int5) equations {
+	eqts := make(equations, 3)
+	for i := 0; i < 3; i++ {
+		eqts[i] = equation{ints[i], ints[i+1], ints[i+2]}
+	}
+	return eqts
+}
+
+func (eqts equations) isValid() bool {
+	anss := make(map[answer]struct{})
+	for i := 0; i < 2; i++ {
+		ans := eqts[i].solve(eqts[i+1])
+		//fmt.Println(ans)
+		if ans.isValid == false {
+			return false
+		}
+		anss[ans] = struct{}{}
+		if len(anss) > 1 {
+			return false
+		}
+	}
+	return true
+}
+
+type int5 [5]int
+
+func main() {
+	for _, data := range []struct {
+		input  int5
+		output bool
+	}{
+		{int5{1, 1, 2, 3, 5}, true},
+		{int5{4, 2, 4, 5, 7}, false},
+		{int5{4, 1, 2, -3, 8}, true},
+	} {
+		fmt.Println(newEquations(data.input).isValid() == data.output)
+
+	}
+}