diff options
| author | Jeroen van Rijn <Kelimion@users.noreply.github.com> | 2021-07-26 15:07:58 +0200 |
|---|---|---|
| committer | Jeroen van Rijn <Kelimion@users.noreply.github.com> | 2021-08-11 20:59:51 +0200 |
| commit | 9646d1f2b842dd22893b3a70eb9c8aef9b1ffa75 (patch) | |
| tree | 613b7eb5c6c88ceea0359f109ada9a2087f311bf | |
| parent | 5f7aeb30450cb9ca794ffe45949f77ed67836ecf (diff) | |
big: Add `submod`, `mulmod`, `sqrmod`.
| -rw-r--r-- | core/math/big/basic.odin | 38 | ||||
| -rw-r--r-- | core/math/big/example.odin | 4 |
2 files changed, 37 insertions, 5 deletions
diff --git a/core/math/big/basic.odin b/core/math/big/basic.odin index fe443db87..52992e15f 100644 --- a/core/math/big/basic.odin +++ b/core/math/big/basic.odin @@ -656,7 +656,7 @@ sqr :: proc(dest, src: ^Int) -> (err: Error) { divmod.
Both the quotient and remainder are optional and may be passed a nil.
*/
-int_div :: proc(quotient, remainder, numerator, denominator: ^Int) -> (err: Error) {
+int_divmod :: proc(quotient, remainder, numerator, denominator: ^Int) -> (err: Error) {
/*
Early out if neither of the results is wanted.
*/
@@ -692,7 +692,12 @@ int_div :: proc(quotient, remainder, numerator, denominator: ^Int) -> (err: Erro return err;
}
-div :: proc{ int_div, };
+divmod :: proc{ int_divmod, };
+
+int_div :: proc(quotient, numerator, denominator: ^Int) -> (err: Error) {
+ return int_divmod(quotient, nil, numerator, denominator);
+}
+div :: proc { int_div, };
/*
remainder = numerator % denominator.
@@ -700,7 +705,7 @@ div :: proc{ int_div, }; denominator < remainder <= 0 if denominator < 0
*/
int_mod :: proc(remainder, numerator, denominator: ^Int) -> (err: Error) {
- if err = div(nil, remainder, numerator, denominator); err != .None { return err; }
+ if err = divmod(nil, remainder, numerator, denominator); err != .None { return err; }
z: bool;
if z, err = is_zero(remainder); z || denominator.sign == remainder.sign { return .None; }
@@ -718,6 +723,33 @@ int_addmod :: proc(remainder, number, addend, modulus: ^Int) -> (err: Error) { addmod :: proc { int_addmod, };
/*
+ remainder = (number - decrease) % modulus.
+*/
+int_submod :: proc(remainder, number, decrease, modulus: ^Int) -> (err: Error) {
+ if err = add(remainder, number, decrease); err != .None { return err; }
+ return mod(remainder, remainder, modulus);
+}
+submod :: proc { int_submod, };
+
+/*
+ remainder = (number * multiplicand) % modulus.
+*/
+int_mulmod :: proc(remainder, number, multiplicand, modulus: ^Int) -> (err: Error) {
+ if err = mul(remainder, number, multiplicand); err != .None { return err; }
+ return mod(remainder, remainder, modulus);
+}
+mulmod :: proc { int_mulmod, };
+
+/*
+ remainder = (number * number) % modulus.
+*/
+int_sqrmod :: proc(remainder, number, modulus: ^Int) -> (err: Error) {
+ if err = sqr(remainder, number); err != .None { return err; }
+ return mod(remainder, remainder, modulus);
+}
+sqrmod :: proc { int_sqrmod, };
+
+/*
==========================
Low-level routines
==========================
diff --git a/core/math/big/example.odin b/core/math/big/example.odin index 5a7976a88..ceb047f74 100644 --- a/core/math/big/example.odin +++ b/core/math/big/example.odin @@ -69,10 +69,10 @@ demo :: proc() { err = set (numerator, 3); err = set (denominator, 2); - err = set (quotient, 3); + err = set (quotient, 5); err = zero(remainder); - err = addmod(remainder, numerator, denominator, quotient); + err = mulmod(remainder, numerator, denominator, quotient); if err != .None { fmt.printf("Error: %v\n", err); } else { |