From e46ead1681b24c75624c33f167c530e633e40440 Mon Sep 17 00:00:00 2001
From: mzuenni <michi.zuendorf@gmail.com>
Date: Sat, 3 Aug 2024 00:14:36 +0200
Subject: more tests

---
 test/math/polynomial.cpp | 153 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 153 insertions(+)
 create mode 100644 test/math/polynomial.cpp

(limited to 'test/math')

diff --git a/test/math/polynomial.cpp b/test/math/polynomial.cpp
new file mode 100644
index 0000000..f4a9486
--- /dev/null
+++ b/test/math/polynomial.cpp
@@ -0,0 +1,153 @@
+#include "../util.h"
+#include <math/shortModInv.cpp>
+constexpr ll mod = 1'394'633'899;
+#include <math/polynomial.cpp>
+
+poly randomPoly(int deg) {
+	poly p;
+	p.data = Random::integers<ll>(deg + 1, 0, mod);
+	return p;
+}
+
+ll eval(const vector<ll>& p, ll x) {
+	ll res = 0;
+	for (ll i = 0, j = 1; i < sz(p); i++, j = (j * x) % mod) {
+		res += j * p[i];
+		res %= mod;
+	}
+	return res;
+}
+
+void test_eval() {
+	int queries = 0;
+	for (int tries = 0; tries < 100'000; tries++) {
+		int deg = Random::integer<int>(1, 30);
+		vector<ll> tmp = Random::integers<ll>(deg + 1, 0, mod);
+		poly p(deg);
+		for (int i = 0; i <= deg; i++) p[i] = tmp[i];
+
+		for (int i = 0; i <= deg + 7; i++) {
+			ll x = Random::integer<ll>(0, mod);
+
+			ll got = p(x);
+			ll expected = eval(tmp, x);
+
+			if (got != expected) cerr << "got: " << got << ", expected: " << expected << FAIL;
+		}
+		queries += deg + 1;
+	}
+	cerr << "tested eval: " << queries << endl;
+}
+
+void test_add() {
+	int queries = 0;
+	for (int tries = 0; tries < 100'000; tries++) {
+		int n = Random::integer<int>(1, 30);
+		int m = Random::integer<int>(1, 30);
+		auto a = randomPoly(n);
+		auto b = randomPoly(m);
+
+		auto c = a;
+		c += b;
+
+		if (sz(c) > sz(a) && sz(c) > sz(b)) cerr << "error: wrong degree" << FAIL;
+
+		for (int i = 0; i <= n + m + 7; i++) {
+			ll x = Random::integer<ll>(0, mod);
+
+			ll got = c(x);
+			ll expected = (a(x) + b(x)) % mod;
+
+			if (got != expected) cerr << "got: " << got << ", expected: " << expected << FAIL;
+		}
+		queries += n + m;
+	}
+	cerr << "tested add: " << queries << endl;
+}
+
+void test_mul() {
+	int queries = 0;
+	for (int tries = 0; tries < 100'000; tries++) {
+		int n = Random::integer<int>(1, 30);
+		int m = Random::integer<int>(1, 30);
+		auto a = randomPoly(n);
+		auto b = randomPoly(m);
+
+		auto c = a * b;
+		if (sz(c) > sz(a) + sz(b) - 1) cerr << "error: wrong degree" << FAIL;
+
+		for (int i = 0; i <= n + m + 7; i++) {
+			ll x = Random::integer<ll>(0, mod);
+
+			ll got = c(x);
+			ll expected = (a(x) * b(x)) % mod;
+
+			if (got != expected) cerr << "got: " << got << ", expected: " << expected << FAIL;
+		}
+		queries += n + m;
+	}
+	cerr << "tested mul: " << queries << endl;
+}
+
+void test_shift() {
+	int queries = 0;
+	for (int tries = 0; tries < 100'000; tries++) {
+		int n = Random::integer<int>(1, 30);
+		int m = Random::integer<int>(1, 30);
+		auto a = randomPoly(n);
+
+		auto b = a << m;
+		if (sz(b) > sz(a)) cerr << sz(a) << " " << sz(b) << endl;
+		if (sz(b) > sz(a)) cerr << "error: wrong degree" << FAIL;
+
+		for (int i = 0; i <= n + 7; i++) {
+			ll x = Random::integer<ll>(0, mod);
+
+			ll got = b(x);
+			ll expected = a((x + m) % mod);
+
+			if (got != expected) {
+				for (ll y : b.data) cerr << y << " ";
+				cerr << endl;
+			}
+			if (got != expected) cerr << "got: " << got << ", expected: " << expected << FAIL;
+		}
+		queries += n;
+	}
+	cerr << "tested shift: " << queries << endl;
+}
+
+void test_divmod() {
+	int queries = 0;
+	for (int tries = 0; tries < 100'000; tries++) {
+		int n = Random::integer<int>(1, 30);
+		int m = Random::integer<int>(1, 30);
+		auto a = randomPoly(n);
+		auto b = randomPoly(m);
+
+		auto [div, rem] = a.divmod(b);
+		if (sz(rem) > sz(b)) cerr << "error: wrong degree (rem)" << FAIL;
+		if (sz(div) > 1 + max<ll>(0, sz(a) - sz(b))) cerr << "error: wrong degree (div)" << FAIL;
+
+		for (int i = 0; i <= n + m; i++) {
+			ll x = Random::integer<ll>(0, mod);
+			ll d = multInv(b(x), mod);
+
+			ll got = (div(x) + rem(x) * d) % mod;
+			ll expected = (a(x) * d) % mod;
+
+			if (got != expected) cerr << "got: " << got << ", expected: " << expected << FAIL;
+		}
+		queries += n + m;
+	}
+	cerr << "tested divmod: " << queries << endl;
+}
+	
+int main() {
+	test_eval();
+	test_add();
+	test_mul();
+	test_shift();
+	test_divmod();
+}
+
-- 
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