/*
1. 今年有多少天 = 这个月之前有多少天 + 今天是当月的第几天 + 闰年补充天
2.  这个月之前有多少天 -> 前缀和 制备好 
*/

class Solution {
    static int MONTH_NUMBER = 12;
    static int[] dayOfMonth = {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
    static int[] prefixSum = initPrefixSum();


    public int dayOfYear(String date) {
        String[] dateTime = date.split("-");
        int year = Integer.parseInt(dateTime[0]);
        int month = Integer.parseInt(dateTime[1]);
        int day = Integer.parseInt(dateTime[2]);

        int extra =  isLeapYear(year) && month > 2 ? 1 : 0 ;
        return prefixSum[month-1] + day + extra;
    }

    private static int[] initPrefixSum(){
        int[] prefixSum = new int[MONTH_NUMBER + 1];

        for (int i = 1; i <= MONTH_NUMBER ; i++){
            prefixSum[i] += prefixSum[i-1] + dayOfMonth[i];
        }
        return prefixSum;
    }

    private boolean isLeapYear(int y){
        return (y % 4 == 0) && !(y % 100 == 0 && y % 400 != 0);
    }
}