#include "cstdio" #include "string" using namespace std; int days[13] = {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; bool is_leap_year(int year){ return (year%100 != 0 && year%4 == 0) || (year%100 == 0 && year%400 == 0); } void add_days(int curr_year, int curr_month, int curr_day, in...