add script 2

example.txt

@@ -1,5 +1,4 @@
-* -> fiona: 138
-* -> zhonghao: 48.5
-* -> xx: 15
-chao
-aria
+* -> xx: 30
+* -> chao: 69
+hao
+fei

simplify_dfs.py

@@ -0,0 +1,73 @@
+from collections import defaultdict
+import math
+'''
+## Settle money, 类似splitwise, 类似465
+
+https://leetcode.com/problems/optimal-account-balancing/description/
+
+    1. input 是transaction list, [[payer: 'A',amount: 4000,payees: ['A', 'B', 'C', 'D'.]],   [payer: 'B',amount: 2000,payees: ['A', 'B']]]
+
+    2. return  C转A 2000， D转A…..，B转A….这样
+
+
+O(n!)
+'''
+class Solution:
+    def minTransfers(self, input_transactions):
+        balance = defaultdict(int)
+        transactions = []
+        for trans in input_transactions:
+            amount = trans['amount']
+            payer = trans['payer']
+            payees = trans['payees']
+            # Split the transaction amount among the payees (excluding the payer)
+            per_person = round(amount / len(payees))
+            for payee in payees:
+                transactions.append((payer, payee, per_person))
+        for from_, to, amt in transactions:
+            balance[to] += amt
+            balance[from_] -= amt
+
+        # Filter out zero balances and create a list of non-zero balances
+        debts = list(filter(lambda x: x != 0, balance.values()))
+        people = list(filter(lambda x: balance[x] != 0, balance.keys()))
+        # Helper function to find the min transactions to settle starting from 'index'
+        def backtrack(index):
+            # Skip already settled accounts
+            while index < len(debts) and debts[index] == 0:
+                index += 1
+            if index == len(debts):
+                return [], 0
+
+            min_txns = math.inf
+            min_trans_list = []
+            for j in range(index + 1, len(debts)):
+                # Pruning. debts[j] must be non zero and of different sign
+                if debts[j] * debts[index] < 0:
+                    # Temporarily settle the debt
+                    debts[j] += debts[index]
+                    next_trans_list, num_txns = backtrack(index + 1)
+                    # If better solution found, update the result
+                    if num_txns + 1 < min_txns:
+                        min_txns = num_txns + 1
+                        amt = abs(debts[index])
+                        # Determine the payer and payee based on the sign of debts[index]
+                        transaction = f"{people[index] if debts[index] > 0 else people[j]} pays {people[j] if debts[index] > 0 else people[index]} ${amt}"
+                        # Include current transaction in the list
+                        min_trans_list = next_trans_list + [transaction]
+                    # Backtrack the temporary change
+                    debts[j] -= debts[index]
+            return min_trans_list, min_txns
+
+        transactions, min_txns = backtrack(0)
+        return transactions, min_txns
+
+# Example usage:
+input_transactions = [
+    {'payer': 'xia', 'amount': 15, 'payees': ['xia', 'hao']},
+    {'payer': 'hao', 'amount': 62, 'payees': ['xia', 'hao']}
+]
+
+solution = Solution()
+final_transactions = solution.minTransfers(input_transactions)
+print(final_transactions)