Data commit

Task/Ranking-methods/Go/ranking-methods.go

@@ -0,0 +1,113 @@
+package main
+
+import (
+	"fmt"
+	"sort"
+)
+
+type rankable interface {
+	Len() int
+	RankEqual(int, int) bool
+}
+
+func StandardRank(d rankable) []float64 {
+	r := make([]float64, d.Len())
+	var k int
+	for i := range r {
+		if i == 0 || !d.RankEqual(i, i-1) {
+			k = i + 1
+		}
+		r[i] = float64(k)
+	}
+	return r
+}
+
+func ModifiedRank(d rankable) []float64 {
+	r := make([]float64, d.Len())
+	for i := range r {
+		k := i + 1
+		for j := i + 1; j < len(r) && d.RankEqual(i, j); j++ {
+			k = j + 1
+		}
+		r[i] = float64(k)
+	}
+	return r
+}
+
+func DenseRank(d rankable) []float64 {
+	r := make([]float64, d.Len())
+	var k int
+	for i := range r {
+		if i == 0 || !d.RankEqual(i, i-1) {
+			k++
+		}
+		r[i] = float64(k)
+	}
+	return r
+}
+
+func OrdinalRank(d rankable) []float64 {
+	r := make([]float64, d.Len())
+	for i := range r {
+		r[i] = float64(i + 1)
+	}
+	return r
+}
+
+func FractionalRank(d rankable) []float64 {
+	r := make([]float64, d.Len())
+	for i := 0; i < len(r); {
+		var j int
+		f := float64(i + 1)
+		for j = i + 1; j < len(r) && d.RankEqual(i, j); j++ {
+			f += float64(j + 1)
+		}
+		f /= float64(j - i)
+		for ; i < j; i++ {
+			r[i] = f
+		}
+	}
+	return r
+}
+
+type scores []struct {
+	score int
+	name  string
+}
+
+func (s scores) Len() int                { return len(s) }
+func (s scores) RankEqual(i, j int) bool { return s[i].score == s[j].score }
+func (s scores) Swap(i, j int)           { s[i], s[j] = s[j], s[i] }
+func (s scores) Less(i, j int) bool {
+	if s[i].score != s[j].score {
+		return s[i].score > s[j].score
+	}
+	return s[i].name < s[j].name
+}
+
+var data = scores{
+	{44, "Solomon"},
+	{42, "Jason"},
+	{42, "Errol"},
+	{41, "Garry"},
+	{41, "Bernard"},
+	{41, "Barry"},
+	{39, "Stephen"},
+}
+
+func main() {
+	show := func(name string, fn func(rankable) []float64) {
+		fmt.Println(name, "Ranking:")
+		r := fn(data)
+		for i, d := range data {
+			fmt.Printf("%4v - %2d %s\n", r[i], d.score, d.name)
+		}
+	}
+
+	sort.Sort(data)
+	show("Standard", StandardRank)
+	show("\nModified", ModifiedRank)
+	show("\nDense", DenseRank)
+	show("\nOrdinal", OrdinalRank)
+	show("\nFractional", FractionalRank)
+}