Sage impls single-files code&tests

number-theory.sage

@@ -77,3 +77,32 @@ def inv_mod(a, N):
     if g != 1:
         raise Exception("inv_mod err, g!=1")
     return mod(x, N)
+
+# Tests
+
+#####
+# Chinese Remainder Theorem tests
+a_i = [5, 3, 10]
+m_i = [7, 11, 13]
+assert crt(a_i, m_i) == 894
+
+a_i = [3, 8]
+m_i = [13, 17]
+assert crt(a_i, m_i) == 42
+
+
+#####
+# gcd, using Binary Euclidean algorithm tests
+assert gcd(21, 12) == 3
+assert gcd(1_426_668_559_730, 810_653_094_756) == 1_417_082
+
+assert gcd_recursive(21, 12) == 3
+
+#####
+# Extended Euclidean algorithm tests
+assert egcd(7, 19) == (1, -8, 3)
+assert egcd_recursive(7, 19) == (1, -8, 3)
+
+#####
+# Inverse modulo N tests
+assert inv_mod(7, 19) == 11