I've been doing this greedy problem, and my solution fails on test case 6. For small inputs it seems to work, but for large inputs it produces strange results.

Problem: 854C - Planning

My Solution: [submission:31321238]

Someone else's accepted solution: 30195313 — They used a priority_queue while I used a sorted vector. This should achieve the same result, and I do not think it is the data structure that is the problem.

Any idea what the problem might be?