An interesting Algorithm

Using system; using system. collections. generic; using system. text; namespace cbirthday {class program {/// <summary> /// both xiaohe and Xiaoqiang are students of instructor Zhang. The birthday of instructor Zhang is mm-n, /// both of them know that Mr. Zhang's life is one day in the following 10 groups. /// Mr. Zhang told James about m and gave Xiao Qiang the N value, /// Teacher Zhang asked them if they knew his birthday was that day? /// March 4 March 5 March 8 June 4 June 7 /// September 1 September 5 December 1 /// December 2 December 8 /// James said: If I do not know, xiaoqiang certainly does not know either. // Xiaoqiang said: I did not know either, but now I know it. // James said: Oh, then I also know // which day is Miss Zhang's birthday Based on the conversation above ?? ////// </Summary> /// <Param name = "ARGs"> </param> static void main (string [] ARGs) {dictionary <int, int []> birthdays = new dictionary <int, int []> (); birthdays. add (1, new int [] {3, 4}); birthdays. add (2, new int [] {3, 5}); birthdays. add (3, new int [] {3, 8}); birthdays. add (4, new int [] {6, 4}); birthdays. add (5, new int [] {6, 7}); birthdays. add (6, new int [] {9, 1}); birthdays. add (7, new I NT [] {9, 5}); birthdays. add (8, new int [] {12, 1}); birthdays. add (9, new int [] {12, 2}); birthdays. add (10, new int [] {12, 8}); analysebirthday (birthdays); If (birthdays. keys. count> 0) {foreach (keyvaluepair <int, int []> item in birthdays) {console. writeline ("Miss Zhang's birthday may be: {0} {1}", item. value [0], item. value [1]) ;}} else {console. writeline ("unsolved");} console. readline ();} Private Static void Analysebirthday (Dictionary <int, int []> birthdays) {// days: a set of all N values, tkey: N value, tvalue: number of occurrences dictionary <int, int> days = new dictionary <int, int> (); // months: All n Value Sets, tkey: m value, tvalue: number of occurrences dictionary <int, int> months = new dictionary <int, int> (); // traverse birthdays and assign values to days and months foreach (keyvaluepair <int, int []> item in birthdays) {If (days. containskey (item. value [1]) days [item. value [1] + = 1; else days. A Dd (item. value [1], 1); If (Months. containskey (item. value [0]) months [item. value [0] + = 1; else months. add (item. value [0], 1);} // declare a temporary list: tempdays, used to store the n Value List <int> tempdays = new list <int> (); // declare a temporary list: tempmonths, used to store the M Value List <int> tempmonths = new list <int> (); // declare a temporary list: keys, list of tkey values used to store birthdays <int> keys = new list <int> (); // you can find the corresponding values of N values that may only appear once in a birthday, save it to tempdays // obtain the m value corresponding to the unique N value, and Save it to tempmonths for foreach (keyvaluepair <int, int> item in days) {If (item. value = 1) {tempdays. add (item. key); foreach (keyvaluepair <int, int []> birthday in birthdays) {If (birthday. value [1] = item. key) {If (! Tempmonths. contains (birthday. value [0]) tempmonths. add (birthday. value [0]) ;}}}// traverses all possible birthdays and obtains the corresponding tkey of all // values in tempmonths in birthdays, store in keys foreach (INT month in tempmonths) {foreach (keyvaluepair <int, int []> birthday in birthdays) if (birthday. value [0] = month) keys. add (birthday. key);} // traverse keys, remove the impossible birthday of M = key in birthdays // remove the corresponding value in months // the number of times that a day appears minus one foreach (INT key in keys) {months. remove (Birthdays [Key] [0]); days [birthdays [Key] [1]-= 1; birthdays. remove (key);} // remove the impossible birthday in days (INT day in tempdays) {days. remove (day);} // clear tempdays. clear (); // clear keys. clear (); // traverses all possible birthdays and removes the date foreach (keyvaluepair <int, int> item in days) that has occurred twice in the N value. {If (item. value> 1) {tempdays. add (item. key); foreach (keyvaluepair <int, int []> birthday in birthdays) {If (birthday. value [1] = Item. Key) {If (! Keys. contains (birthday. key) keys. add (birthday. key); months [birthday. value [0]-= 1 ;}}} foreach (INT key in keys) birthdays. remove (key); keys. clear (); tempmonths. clear (); // traverses all possible birthdays and removes the date foreach (keyvaluepair <int, int> item in months) that has occurred twice in M values. {If (item. value> 1) if (! Tempmonths. contains (item. key) tempmonths. add (item. key);} foreach (INT month in tempmonths) {foreach (keyvaluepair <int, int []> item in birthdays) if (item. value [0] = month) if (! Keys. Contains (item. Key) keys. Add (item. Key) ;}foreach (INT key in keys) birthdays. Remove (key );}}}