Merge pull request #148 from Smit-create/mod_gcd

Add gcd and lcm math functions

Author: certik

integration_tests/test_math.py

@@ -1,5 +1,5 @@
 from math import (factorial, isqrt, perm, comb, degrees, radians, exp, pow,
-                  ldexp, fabs)
+                  ldexp, fabs, gcd, lcm)
 from ltypes import i32, f64
 
 
@@ -65,6 +65,25 @@ def test_fabs():
     print(i, j)
 
 
+def test_gcd():
+    i: i32
+    i = gcd(10, 4)
+    assert i == 2
+    i = gcd(21, 14)
+    assert i == 7
+    i = gcd(21, -12)
+    assert i == 3
+
+def test_lcm():
+    i: i32
+    i = lcm(10, 4)
+    assert i == 20
+    i = lcm(21, 14)
+    assert i == 42
+    i = lcm(21, -12)
+    assert i == 84
+
+
 test_factorial_1()
 test_comb()
 test_isqrt()
@@ -75,3 +94,5 @@ def test_fabs():
 test_pow()
 test_fabs()
 test_ldexp()
+test_gcd()
+test_lcm()

src/runtime/math.py

@@ -109,3 +109,40 @@ def pow(x: f64, y: f64) -> f64:
     Return `x` raised to the power `y`.
     """
     return x**y
+
+
+def mod(a: i32, b: i32) -> i32:
+    """
+    Returns a%b
+    """
+    return a - (a//b)*b
+
+
+def gcd(a: i32, b: i32) -> i32:
+    """
+    Returns greatest common divisor of `a` and `b`
+    """
+    temp: i32
+    if a < 0:
+        a = -a
+    if b < 0:
+        b = -b
+    while b != 0:
+        a = mod(a, b)
+        temp = a
+        a = b
+        b = temp
+    return a
+
+
+def lcm(a: i32, b: i32) -> i32:
+    """
+    Returns least common multiple of `a` and `b`
+    """
+    if a < 0:
+        a = -a
+    if b < 0:
+        b = -b
+    if a*b == 0:
+        return 0
+    return (a*b)//gcd(a, b)