Leetcode 2742. Painting the Walls

Pick a subset of walls for the paid painter to minimize total cost such that his total working time allows the free painter (who paints any wall in 1 time unit but only while the paid painter is busy) to finish the remaining walls. Equivalently, it's a 0/1 knapsack/DP: choosing wall i contributes weight time[i]+1 and you need total weight ≥ n at minimum cost.