i just needs to be from 0 to n-1

[fvdcx]

for (int i = 0; i < n; ++i) max_profit = max(max_profit, f[i] + g[i]); I think i would better range from 0 to n-1 [0, n-1) Because the case i = 0 and the case i = n -1 are the same.