Spot Capacity Round Trips tests accept the two largest rising runs

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@peter1001136 已经在做这个了。

开始于 2026年11月13日。

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Issue 类型
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技术栈
cpp, json
领域
testing, tooling

调研方向

从 problem-bank/judges.json 开始，查找 Spot Capacity Round Trips 的测试用例。添加报告中的输入 [[1,2,4,2,5,7,2,4,9,0]]，其预期值为 13，然后按要求重新生成 judges。完成标准是：新增用例能够拒绝所描述的错误解法，同时正确解法仍能通过。

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描述

Observed behavior

In Spot Capacity Round Trips (best-time-to-buy-and-sell-stock-iii, LeetCode 123), the built-in tests accept a solution that splits the prices into rising runs and adds the two largest run gains. It passes 6/6, the same as a correct solution.

class Solution {
public:
    int bestTwoRoundTrips(vector<int>& prices) {
        vector<int> gains;
        int n = prices.size(), i = 0;
        while (i < n - 1) {
            int j = i;
            while (j + 1 < n && prices[j + 1] >= prices[j]) j++;
            if (prices[j] > prices[i]) gains.push_back(prices[j] - prices[i]);
            i = j > i ? j + 1 : i + 1;
        }
        sort(gains.rbegin(), gains.rend());
        int total = 0;
        for (int k = 0; k < (int)gains.size() && k < 2; k++) total += gains[k];
        return total;
    }
};

It never joins two runs into one trade across a dip. On [1,2,4,2,5,7,2,4,9,0] the runs gain 3, 5 and 7, so it returns 12. The answer is 13: buy at 1 and sell at 7, then buy at 2 and sell at 9. Every built-in case has at most two rising runs, or its best pair of trades is already two whole runs, so the tests cannot tell the two apart. The same solution written in Python also passes all 6 and returns 12 on the case above, since every language runs the same judge cases.

Expected behavior

At least one built-in case has three or more rising runs where the best two trades span a dip, so this solution fails the tests. A correct solution still passes every case.

Reproduction
  1. Run CodeTrial at the revision below and open Spot Capacity Round Trips with C++.
  2. Paste the solution above and run the tests. All 6 built-in cases pass.
  3. Under "Add a case", enter [[1,2,4,2,5,7,2,4,9,0]] as the input and 13 as the expected value, then run again. The new case fails with got 12.
CodeTrial version

codetrial 0.1.0 (c54aed7), built from source. The judge for this problem is unchanged between c54aed7 and main at d0544857.

Environment
  • OS: Windows 11 with the server in WSL2
  • Browser: Chrome 157.0.8103.51
  • Language: C++
  • Interview loop: Coding
  • Problem: Spot Capacity Round Trips (LeetCode 123)
  • REACTO or STAR step: Test
  • Reconnect: None
Sanitized evidence

All 6 built-in cases pass, and the added case fails with got 12:

image
Public data confirmation
  • I removed credentials, session tokens, candidate recordings, and personal interview content from this public report.

I would like to fix this by adding that case to problem-bank/judges.json and regenerating the judges. Please assign it to me.

主要语言
Rust
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