Minimum money required before transactions

Array Greedy Sorting

42.0% acceptance

Feb 25, 2026

415

You are given a 0-indexed 2D integer array transactions, where transactions[i] = [costi, cashbacki]. The array describes transactions, where each transaction must be completed exactly once in some order. At any given moment, you have some amount of money. In order to complete transaction i, money >= costi must hold true. After performing a transaction, money = money - costi + cashbacki. Return the minimum amount of money required before any transaction so that all of the transactions can be completed regardless of the order of the transactions.

Solution

Rust

Time O(n)

Space O(1)

LeetCode

solution.rs

impl Solution {
  pub fn minimum_money(transactions: Vec<Vec<i32>>) -> i64 {
    let mut total_loss: i64 = 0;
    for t in &transactions {
      total_loss += (t[0] - t[1]).max(0) as i64;
    }
    let mut ans: i64 = 0;
    for t in &transactions {
      let cost = t[0] as i64;
      let cashback = t[1] as i64;
      let loss = (cost - cashback).max(0);
      // Worst case: do this transaction last, needing total_loss - loss + cost
      let worst = total_loss - loss + cost;
      ans = ans.max(worst);
    }
    ans
  }
}