Merge pull request #3811 from gramosg/ch106

Challenge 106 (Go)

5 files changed, 122 insertions, 0 deletions

diff --git a/challenge-106/guillermo-ramos/go/ch-1.go b/challenge-106/guillermo-ramos/go/ch-1.go
new file mode 100644
index 0000000000..df60fc25a3
--- /dev/null
+++ b/challenge-106/guillermo-ramos/go/ch-1.go
@@ -0,0 +1,15 @@
+package ch106
+
+import "sort"
+
+func MaximumGap(numbers sort.IntSlice) int {
+	sort.Sort(numbers)
+	var maxGap int
+	for i := 0; i < len(numbers)-1; i++ {
+		diff := numbers[i+1] - numbers[i]
+		if diff > maxGap {
+			maxGap = diff
+		}
+	}
+	return maxGap
+}
diff --git a/challenge-106/guillermo-ramos/go/ch-2.go b/challenge-106/guillermo-ramos/go/ch-2.go
new file mode 100644
index 0000000000..14a16a677d
--- /dev/null
+++ b/challenge-106/guillermo-ramos/go/ch-2.go
@@ -0,0 +1,59 @@
+package ch106
+
+import (
+	"fmt"
+	"strconv"
+)
+
+type PerioDec struct {
+	digits      []int
+	periodicIdx int
+}
+
+func (d PerioDec) String() (s string) {
+	for i, v := range d.digits {
+		if i == 1 {
+			s = fmt.Sprint(s, ".")
+		}
+		if i == d.periodicIdx {
+			s = fmt.Sprint(s, "(")
+		}
+		s = fmt.Sprint(s, strconv.Itoa(v))
+	}
+	if d.periodicIdx != -1 {
+		s = fmt.Sprint(s, ")")
+	}
+	return
+}
+
+func DecimalString(n, d int) string {
+	dec := PerioDec{periodicIdx: -1}
+	numeratorIdxs := make(map[int]int)
+
+	maxDecimals := 20
+	for i := 0; i <= maxDecimals; i++ {
+		if idx, ok := numeratorIdxs[n]; ok && idx > 0 {
+			dec.periodicIdx = idx
+			break
+		}
+
+		q := 0
+		r := n
+		for r >= d {
+			r = r - d
+			q++
+		}
+
+		numeratorIdxs[n] = i
+		dec.digits = append(dec.digits, q)
+
+		n = r * 10
+
+		if r == 0 {
+			break
+		}
+
+	}
+
+	return dec.String()
+}
diff --git a/challenge-106/guillermo-ramos/go/ch106_test.go b/challenge-106/guillermo-ramos/go/ch106_test.go
new file mode 100644
index 0000000000..ca80e137b7
--- /dev/null
+++ b/challenge-106/guillermo-ramos/go/ch106_test.go
@@ -0,0 +1,42 @@
+package ch106
+
+import "testing"
+
+type MaxGapCase struct {
+	input []int
+	wants int
+}
+
+func TestMaximumGap(t *testing.T) {
+	expected := []MaxGapCase{
+		{[]int{2, 9, 3, 5}, 4},
+		{[]int{1, 3, 8, 2, 0}, 5},
+		{[]int{5}, 0},
+	}
+	for _, c := range expected {
+		res := MaximumGap(c.input)
+		if res != c.wants {
+			t.Errorf("MaximumGap(%v) returned '%d' but expected '%d'",
+				c.input, res, c.wants)
+		}
+	}
+}
+
+type DecStringInput struct {
+	n, d int
+}
+
+func TestDecimalString(t *testing.T) {
+	expected := map[DecStringInput]string{
+		{n: 1, d: 3}:  "0.(3)",
+		{n: 1, d: 2}:  "0.5",
+		{n: 5, d: 66}: "0.0(75)",
+	}
+	for input, wants := range expected {
+		res := DecimalString(input.n, input.d)
+		if res != wants {
+			t.Errorf("DecimalString(%d, %d) returned '%s' but expected '%s'",
+				input.n, input.d, res, wants)
+		}
+	}
+}
diff --git a/challenge-106/guillermo-ramos/go/go.mod b/challenge-106/guillermo-ramos/go/go.mod
new file mode 100644
index 0000000000..dd59d04ad4
--- /dev/null
+++ b/challenge-106/guillermo-ramos/go/go.mod
@@ -0,0 +1,3 @@
+module example.com/ch106
+
+go 1.16
diff --git a/challenge-106/guillermo-ramos/go/run_tests.sh b/challenge-106/guillermo-ramos/go/run_tests.sh
new file mode 100755
index 0000000000..20e7774e09
--- /dev/null
+++ b/challenge-106/guillermo-ramos/go/run_tests.sh
@@ -0,0 +1,3 @@
+#!/bin/sh
+
+go test -v