diff --git a/tspy/solvers/utils.py b/tspy/solvers/utils.py
index 0a1a00c..5371c9c 100644
--- a/tspy/solvers/utils.py
+++ b/tspy/solvers/utils.py
@@ -1,5 +1,13 @@
+import numpy as np
+
 def get_cost(tour,tsp):
     ans = 0
     for i in range(len(tour)-1):
         ans += tsp.mat[tour[i],tour[i+1]]
     return ans
+
+
+
+def fast_cost (tour, tsp):
+    t = np.asarray(tour)
+    return tsp.mat[t, np.roll(tour, -1)].sum()