1 files changed, 122 insertions, 0 deletions
diff --git a/test/math/bigint.cpp b/test/math/bigint.cpp
new file mode 100644
index 0000000..3fc4ac1
--- /dev/null
+++ b/test/math/bigint.cpp
@@ -0,0 +1,122 @@
+#include "../util.h"
+#include <math/bigint.cpp>
+
+template<ll MOD>
+struct modInt {
+	ll value = 0;
+	modInt() {}
+	modInt(const bigint& x) {
+		stringstream a;
+		a << x;
+		string b = a.str();
+		for (ll i = b[0] == '-' ? 1 : 0; i < sz(b); i++) {
+			value *= 10;
+			value += b[i] - '0';
+			value %= MOD;
+		}
+		if (b[0] == '-') value = (MOD - value) % MOD;
+	}
+
+	modInt(ll x) : value(((x % MOD) + MOD) % MOD) {}
+
+	modInt operator+(modInt o) const {return value + o.value;}
+	modInt operator-(modInt o) const {return value - o.value;}
+	modInt operator*(modInt o) const {return value * o.value;}
+
+	modInt& operator+=(modInt o) {return *this = *this + o;}
+	modInt& operator-=(modInt o) {return *this = *this - o;}
+	modInt& operator*=(modInt o) {return *this = *this * o;}
+
+	ll& operator*() {return value;}
+	bool operator==(const modInt& o) const {return value == o.value;}
+	bool operator!=(const modInt& o) const {return value != o.value;}
+};
+
+constexpr ll MOD = 1'394'633'899;
+constexpr ll POOL = 8;
+
+void stress_test() {
+	int queries = 0;
+	for (int tries = 0; tries < 1000; tries++) {
+		vector<modInt<MOD>> expectedPool(POOL);
+		vector<bigint> gotPool(POOL);
+		for (int i = 0; i < POOL; i++) {
+			ll x = Random::integer<ll>(-1'000'000'000'000'000'000ll, 1'000'000'000'000'000'000ll);
+			expectedPool[i] = x;
+			gotPool[i] = x;
+			if (expectedPool[i] != modInt<MOD>(gotPool[i])) cerr << "error: 0" << FAIL;
+		}
+		for (int i = 0; i < 200; i++) {
+			int a = Random::integer<int>(0, POOL);
+			int b = Random::integer<int>(0, POOL);
+			int o = Random::integer<int>(0, 3);
+
+			if (Random::integer<int>(0, 2) == 0) {//x=
+				auto tmpExpected = expectedPool[a];
+				auto tmpGot = gotPool[a];
+
+				if (o == 0) {
+					tmpExpected += expectedPool[b];
+					tmpGot += gotPool[b];
+				}
+				if (o == 1) {
+					tmpExpected -= expectedPool[b];
+					tmpGot -= gotPool[b];
+				}
+				if (o == 2) {
+					tmpExpected -= expectedPool[b];
+					tmpGot -= gotPool[b];
+				}
+
+				if (tmpExpected != modInt<MOD>(tmpGot)) {
+					cerr << gotPool[a];
+					if (o == 0) cerr << "+";
+					if (o == 1) cerr << "-";
+					if (o == 2) cerr << "*";
+					cerr << gotPool[b] << "=" << tmpGot << endl;
+					cerr << "error: 1" << FAIL;
+				}
+
+				expectedPool[b] = tmpExpected;
+				gotPool[b] = tmpGot;
+			} else {//x
+				int c = Random::integer<int>(0, POOL);
+
+				modInt<MOD> tmpExpected;
+				bigint tmpGot;
+
+				if (o == 0) {
+					tmpExpected = expectedPool[a] + expectedPool[b];
+					tmpGot = gotPool[a] + gotPool[b];
+				}
+				if (o == 1) {
+					tmpExpected = expectedPool[a] - expectedPool[b];
+					tmpGot = gotPool[a] - gotPool[b];
+				}
+				if (o == 2) {
+					tmpExpected = expectedPool[a] * expectedPool[b];
+					tmpGot = gotPool[a] * gotPool[b];
+				}
+
+				if (tmpExpected != modInt<MOD>(tmpGot)) {
+					cerr << gotPool[a];
+					if (o == 0) cerr << "+";
+					if (o == 1) cerr << "-";
+					if (o == 2) cerr << "*";
+					cerr << gotPool[b] << "=" << tmpGot << endl;
+					cerr << "error: 2" << FAIL;
+				}
+
+				expectedPool[c] = tmpExpected;
+				gotPool[c] = tmpGot;
+			}
+			queries++;
+		}
+	}
+	cerr << "tested random queries: " << queries << endl;
+}
+	
+int main() {
+	stress_test();
+}
+