Data commit

Task/Fivenum/Go/fivenum-1.go

@@ -0,0 +1,37 @@
+package main
+
+import (
+    "fmt"
+    "math"
+    "sort"
+)
+
+func fivenum(a []float64) (n5 [5]float64) {
+    sort.Float64s(a)
+    n := float64(len(a))
+    n4 := float64((len(a)+3)/2) / 2
+    d := []float64{1, n4, (n + 1) / 2, n + 1 - n4, n}
+    for e, de := range d {
+        floor := int(de - 1)
+        ceil := int(math.Ceil(de - 1))
+        n5[e] = .5 * (a[floor] + a[ceil])
+    }
+    return
+}
+
+var (
+    x1 = []float64{36, 40, 7, 39, 41, 15}
+    x2 = []float64{15, 6, 42, 41, 7, 36, 49, 40, 39, 47, 43}
+    x3 = []float64{
+        0.14082834, 0.09748790, 1.73131507, 0.87636009, -1.95059594,
+        0.73438555, -0.03035726, 1.46675970, -0.74621349, -0.72588772,
+        0.63905160, 0.61501527, -0.98983780, -1.00447874, -0.62759469,
+        0.66206163, 1.04312009, -0.10305385, 0.75775634, 0.32566578,
+    }
+)
+
+func main() {
+    fmt.Println(fivenum(x1))
+    fmt.Println(fivenum(x2))
+    fmt.Println(fivenum(x3))
+}

Task/Fivenum/Go/fivenum-2.go

@@ -0,0 +1,65 @@
+package main
+
+import (
+    "fmt"
+    "math/rand"
+)
+
+func fivenum(a []float64) (n [5]float64) {
+    last := len(a) - 1
+    m := last / 2
+    n[2] = qsel(a, m)
+    q1 := len(a) / 4
+    n[1] = qsel(a[:m], q1)
+    n[0] = qsel(a[:q1], 0)
+    a = a[m:]
+    q3 := last - m - q1
+    n[3] = qsel(a, q3)
+    a = a[q3:]
+    n[4] = qsel(a, len(a)-1)
+    return
+}
+
+func qsel(a []float64, k int) float64 {
+    for len(a) > 1 {
+        px := rand.Intn(len(a))
+        pv := a[px]
+        last := len(a) - 1
+        a[px], a[last] = a[last], pv
+        px = 0
+        for i, v := range a[:last] {
+            if v < pv {
+                a[px], a[i] = v, a[px]
+                px++
+            }
+        }
+        a[px], a[last] = pv, a[px]
+        if px == k {
+            return pv
+        }
+        if k < px {
+            a = a[:px]
+        } else {
+            a = a[px+1:]
+            k -= px + 1
+        }
+    }
+    return a[0]
+}
+
+var (
+    x1 = []float64{36, 40, 7, 39, 41, 15}
+    x2 = []float64{15, 6, 42, 41, 7, 36, 49, 40, 39, 47, 43}
+    x3 = []float64{
+        0.14082834, 0.09748790, 1.73131507, 0.87636009, -1.95059594,
+        0.73438555, -0.03035726, 1.46675970, -0.74621349, -0.72588772,
+        0.63905160, 0.61501527, -0.98983780, -1.00447874, -0.62759469,
+        0.66206163, 1.04312009, -0.10305385, 0.75775634, 0.32566578,
+    }
+)
+
+func main() {
+    fmt.Println(fivenum(x1))
+    fmt.Println(fivenum(x2))
+    fmt.Println(fivenum(x3))
+}