动态规划44（Leetcode983最低票价）

代码：

class Solution {
    public int mincostTickets(int[] days, int[] costs) {
        Integer[] daysArr = Arrays.stream(days).boxed().toArray(Integer[]::new);
        List daysList = Arrays.asList(daysArr);
        int n = days[days.length-1];
        int[] dp = new int[n+1];
        dp[0]=0;
        int[] arr = {1,7,30};
        int minCost = Math.min(Math.min(costs[0],costs[1]),costs[2]);
        for(int i=1;i<=n;i++){
            if(daysList.contains(i)){
                dp[i] = dp[i-1]+minCost;                
                for(int j=0;j
                    int day = arr[j];
                    if(i-day>=0){
                        dp[i] = Math.min(dp[i],dp[i-day]+costs[j]);
                    }else{
                        dp[i] = Math.min(dp[i],dp[0]+costs[j]);
                    }
                }       
            }else{
                dp[i] = dp[i-1];
            }
            // if(daysList.contains(i))System.out.println(dp[i]);
        }
        return dp[n];
    }
}