Data commit

Task/Average-loop-length/V-(Vlang)/average-loop-length.v

@@ -0,0 +1,39 @@
+import rand
+import math
+
+const nmax = 20
+
+fn main() {
+    println(" N    average    analytical    (error)")
+    println("===  =========  ============  =========")
+    for n := 1; n <= nmax; n++ {
+        a := avg(n)
+        b := ana(n)
+        println("${n:3}  ${a:9.4f}  ${b:12.4f}  (${math.abs(a-b)/b*100:6.2f}%)" )
+    }
+}
+
+fn avg(n int) f64 {
+    tests := int(1e4)
+    mut sum := 0
+    for _ in 0..tests {
+        mut v := [nmax]bool{}
+        for x := 0; !v[x];  {
+            v[x] = true
+            sum++
+            x = rand.intn(n) or {0}
+        }
+    }
+    return f64(sum) / tests
+}
+
+fn ana(n int) f64 {
+    nn := f64(n)
+    mut term := 1.0
+    mut sum := 1.0
+    for i := nn - 1; i >= 1; i-- {
+        term *= i / nn
+        sum += term
+    }
+    return sum
+}