classSolution{public:intmincostTickets(vector<int> &days, vector<int> &costs){if(days.size() ==0)return0;intlastday = days.back();vector<int>dp(lastday +1,0);vector<bool>flag(lastday +1,false);for(intd: days) flag[d] =true; dp[0] =0;for(inti =1; i <= lastday; i++...