raise Exception if no solution instead of infinite loop

splitbill.py

@@ -30,10 +30,7 @@ def solve_greedily(
 ) -> dict[tuple[str, str], int]:
     creditors, debitors = split_dict(balances, lambda k, v: v > 0)
     transactions = {}
-    while not all(
-        abs(value) <= tolerance
-        for value in chain(creditors.values(), debitors.values())
-    ):
+    for _ in range(len(balances)):
         for debitor, debit_value in sorted(
             debitors.items(),
             key=lambda x: x[1],
@@ -53,6 +50,13 @@ def solve_greedily(
                     debitors[debitor] = sum_value
                     transactions[debitor, creditor] = credit_value
                 break
+        if all(
+            abs(value) <= tolerance
+            for value in chain(creditors.values(), debitors.values())
+        ):
+            break
+    else:
+         raise ValueError("No solution within tolerance found")
     return transactions