diff --git a/sa.cpp b/sa.cpp
index 3e5f762..371ae41 100644
--- a/sa.cpp
+++ b/sa.cpp
@@ -19,8 +19,8 @@ auto sa::solution::simulated_annealing(int capacity, const std::vector<long long
 		sa::solution neighbor(prev, iteration);
 		neighbor.setneighbor();
 
-		int diff = neighbor.fitness - prev.fitness;
-		if (diff <= 0 || std::exp(-diff / temp) > rand(eng)) {
+		long long diff = neighbor.fitness - prev.fitness;
+		if (diff < 0 || rand(eng) / temp < 0.8) {
 			swap(prev, neighbor);
 		}
 
diff --git a/sa.hpp b/sa.hpp
index bec18ac..44a7f19 100644
--- a/sa.hpp
+++ b/sa.hpp
@@ -95,8 +95,8 @@ class box {
 class solution {
 	std::vector<box> boxes;
 	std::default_random_engine gen;
+	long long fitness;
 	int capacity;
-	int fitness;
 	int iterations;
 	int iteration;
 
@@ -140,7 +140,7 @@ class solution {
 	solution() = default;
 
 	solution(const solution &other, int itr): boxes(other.boxes), gen(other.gen),
-	                                          capacity(other.capacity), fitness(other.fitness),
+	                                          fitness(other.fitness), capacity(other.capacity),
 	                                          iteration(itr) {}
 
 	solution(const std::vector<long long> &items, int capacity):  // Gera a solução inicial