/* Real Magic DOB By: Michael Simnitt (Mindsoft) Date Created: 5/26/17 Purpose: Recreate a real Math Magic trick using AI Acknowledgements: https://plus.maths.org/content/what-day-week-were-you-born (provided the tables and methodology) inspired by: Michael Xanthopoulos (Find the Day of the Week You Were Born!) prog on SoloLearn.com NOTE: If you would like to see the trick in action live, check out the link above there is a video posted there. */ #include using namespace std; int main() { //NOTE: Date should be between 1/1/1900 & 12/31/2059 int day(17); // Place Date of Birth here int month(1); // Place Month of Birth here int year(1942); // Place Year of Birth here int leapOffset(0); //Table- days of the week: string tDays[] = {"sunday","Monday","Tuesday","Wednesday","Thursday","Friday","Saturday"}; //Tables- Math tables for the trick int tMonth[] = {6,2,2,5,0,3,5,1,4,6,2,4}; int tDecade[] = {1,6,5,3,2,0,6,4,3,1,0,5,3,2,0,6}; int tEven[] = {0,0,0,0,1,1,1,1,2,2}; int tOdd[] = {0,0,1,1,1,1,2,2,2,2}; int decade = (year - 1900)/10; //1942-1900= 42, 42/10= (4) int yearOffset = year%10; //get remaining non-decade years, 1942/10= 194r(2) int monthOffset = tMonth[month-1]; //month 1-1= (0), spot [0] in table-Month is (6) int decadeOffset = tDecade[decade]; //spot [4] in table-Decade is decade offset (2) //determine if decade is even or odd (so we know which list to use) decade%2?leapOffset = tOdd[yearOffset]:leapOffset = tEven[yearOffset]; //in our case we use even list, table-even spot //add the day and all offsets together int total = day + monthOffset + decadeOffset + yearOffset + leapOffset; //divide the total by 7 for remainder, 27/7= 3r(6). this is the day of the week string weekday = tDays[(total%7)]; //NOTE: Sunday is 0, Monday 1 ..ect. cout << "decade: " << decade << endl; cout << "year Offset: " << yearOffset << endl; cout << "month Offset: " << monthOffset << endl; cout << "decade Offset: " << decadeOffset << endl; cout << "leap-year Offset: " << leapOffset << endl; cout << "total: " << total << endl; cout << "day #: " << total%7 << endl; cout << "weekday: " << weekday << endl << endl; cout << month << "/" << day << "/" << year << " was a " << weekday << endl; return 0; }