Spot Capacity Round Trips tests accept the two largest rising runs

Aperta Adatta ai principianti
  • Qualcosa non va?
#691 0 commenti 0 reazioni 0 assegnatari Vedi su GitHub

I maintainer di solito rispondono entro 1 giorno

@peter1001136 ci sta già lavorando.

Dal 13/11/2026.

  • #692 di @peter1001136 — aperta

Valutazione

Difficoltà
2/5
Tempo stimato
1-3 ore
Idoneità per principianti
78/100
Tipo di issue
Bug
Chiarezza
Specificata chiaramente
Stato di attività
Attiva
Stack tecnologico
cpp, json
Ambito
testing, tooling

Direzione di ricerca

Inizia da problem-bank/judges.json e trova i casi Spot Capacity Round Trips. Aggiungi l’input segnalato [[1,2,4,2,5,7,2,4,9,0]] con il valore atteso 13, poi rigenera i judge come richiesto. Il lavoro è concluso quando il caso aggiunto rifiuta la soluzione errata descritta, mentre una soluzione corretta continua a passare.

Scritto dal modello di indicizzazione a partire dal testo della issue.

Descrizione

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.

Lingua principale
Rust
Stelle
228
Fork
150
Merge medio
1g 3h
PR unite (30g)
226

Preparare l'ambiente

Come iniziare

  1. Leggi tutta la issue e poi la guida ai contributi del progetto.
  2. Commenta sulla issue per dire che te ne occupi tu — evita che due persone facciano lo stesso lavoro.
  3. Fai un fork del repository e lavora su un branch.
  4. Apri una pull request che faccia riferimento al numero della issue.

Altre issue di sysprog21/codetrial

Tutte le issue di sysprog21/codetrial

Issue simili

Altre issue su Rust

Ricevi le nuove issue nella tua casella

Un breve riepilogo di issue GitHub adatte ai principianti.