判断是否为闰年
class Solution {
public int numberOfDays(int Y, int M) {
int arr[] = {0,31,28,31,30,31,30,31,31,30,31,30,31};
if(is_Leap(Y)&&M==2)
return 29;
else return arr[M];
}
public static boolean is_Leap(int i) {
if(i%4==0&&i%100!=0|| i%400==0) {
return true;
}
return false;
}
}