fix minor errors in tests

2 files changed, 3 insertions, 3 deletions

diff --git a/test/math/linearCongruence.cpp b/test/math/linearCongruence.cpp
index fa01a06..042c842 100644
--- a/test/math/linearCongruence.cpp
+++ b/test/math/linearCongruence.cpp
@@ -14,7 +14,7 @@ void stress_test() {
 	ll work = 0;
 	ll positive = 0;
 	for (ll tries = 0; tries < 500'000; tries++) {
-		ll m = Random::integer<ll>(0, 1'000);
+		ll m = Random::integer<ll>(1, 1'000);
 		ll a = Random::integer<ll>(0, m);
 		ll b = Random::integer<ll>(0, m);
 
@@ -33,7 +33,7 @@ void performance_test() {
 	timer t;
 	hash_t hash = 0;
 	for (int operations = 0; operations < N; operations++) {
-		ll m = Random::integer<ll>(0, 1'0000'000'000);
+		ll m = Random::integer<ll>(1, 1'0000'000'000);
 		ll a = Random::integer<ll>(0, m);
 		ll b = Random::integer<ll>(0, m);
 
diff --git a/test/string/suffixTree.cpp b/test/string/suffixTree.cpp
index 6f3d912..fd2f5ea 100644
--- a/test/string/suffixTree.cpp
+++ b/test/string/suffixTree.cpp
@@ -19,7 +19,7 @@ void stress_test() {
 		auto dfs = [&](auto&& self, string pref, ll node) -> void {
 			auto& [l, r, _, next] = st.tree[node];
 			if (l >= 0) pref += s.substr(l, r - l);
-			if (pref.back() == '#') got[n + 1 - ssize(pref)] = pref;
+			if (!pref.empty() && pref.back() == '#') got[n + 1 - ssize(pref)] = pref;
 			for (auto [__, j] : next) {
 				self(self, pref, j);
 			}