Add edigits program for Acton (#323)

Author: plajjan

bench/algorithm/edigits/1.act

@@ -0,0 +1,56 @@
+# port of 1.py
+import math
+
+ln_tau = math.log(6.283185307179586)
+ln_10 = math.log(float(10))
+
+
+def sum_terms(a: int, b: int) -> (int, int):
+    if b == a + 1:
+        return 1, b
+    mid = (a + b) // 2
+    p_left, q_left = sum_terms(a, mid)
+    p_right, q_right = sum_terms(mid, b)
+    return p_left * q_right + p_right, q_left*q_right
+
+
+def binary_search(n) -> int:
+    a = 0
+    b = 1
+    while not test_k(n, b):
+        a = b
+        b *= 2
+    while b - a > 1:
+        m = (a + b) // 2
+        if test_k(n, m):
+            b = m
+        else:
+            a = m
+    return b
+
+
+def test_k(n, k) -> bool:
+    if k <= 0:
+        return False
+    else:
+        ln_k_factorial = float(k) * (math.log(float(k))-1) + 0.5 * ln_tau
+        log_10_k_factorial = ln_k_factorial / ln_10
+        return (int(log_10_k_factorial) >= n+50)
+
+actor main(env):
+    n = 27 if len(env.argv) < 2 else int(env.argv[1])
+    k = binary_search(n)
+    p, q = sum_terms(0, k - 1)
+    p += q
+    answer = p * (10 ** (n - 1)) // q
+    s = str(answer)
+    for i in range(0, n, 10):
+        if i+10 <= n:
+            print(s[i:i+10] + "\t:" + str(i+10))
+        else:
+            spaces = ""
+            for j in range(0, (10-(len(str(s[i:])))), 1):
+                spaces += " "
+            print(s[i:] + spaces + "\t:" + str(n))
+            #print(f'{s[i:]}{" "*(10-n%10)}\t:{n}')
+    await async env.exit(0)

bench/bench_acton.yaml

@@ -3,6 +3,9 @@ problems:
   - name: helloworld
     source:
       - 1.act
+  - name: edigits
+    source:
+      - 1.act
   - name: pidigits
     source:
       - 1.act