0465. Optimal Account Balancing

https://leetcode.com/problems/optimal-account-balancing

Description

You are given an array of transactions transactions where transactions[i] = [fromi, toi, amounti] indicates that the person with ID = fromi gave amounti $ to the person with ID = toi.

Return the minimum number of transactions required to settle the debt.

Example 1:

**Input:** transactions = [[0,1,10],[2,0,5]]
**Output:** 2
**Explanation:**
Person #0 gave person #1 $10.
Person #2 gave person #0 $5.
Two transactions are needed. One way to settle the debt is person #1 pays person #0 and #2 $5 each.

Example 2:

**Input:** transactions = [[0,1,10],[1,0,1],[1,2,5],[2,0,5]]
**Output:** 1
**Explanation:**
Person #0 gave person #1 $10.
Person #1 gave person #0 $1.
Person #1 gave person #2 $5.
Person #2 gave person #0 $5.
Therefore, person #1 only need to give person #0 $4, and all debt is settled.

Constraints:

• 1 <= transactions.length <= 8

• transactions[i].length == 3

• 0 <= fromi, toi <= 20

• fromi != toi

• 1 <= amounti <= 100

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