Ray's playground

摘要： 1#import"AppController.h"2#defineAWS_ID@"1CKE6MZ6S27EFQ458402"34@implementationAppController56-(id)init7{8self=[superinit];9if(self){10//Initializationcodehere.11}1213returnself;14}1516-(IBAction)fetchBooks:(id)sender17{18[progressstartAnimation:nil];1920NSString*input=[searchFie 阅读全文

摘要： A permutation is an ordered arrangement of objects. For example, 3124 is one possible permutation of the digits 1, 2, 3 and 4. If all of the permutations are listed numerically or alphabetically, we call it lexicographic order. The lexicographic permutations of 0, 1 and 2 are:012 021 102 120 201 210 阅读全文

摘要： Starting with the number 1 and moving to the right in a clockwise direction a 5 by 5 spiral is formed as follows:2122 23 242520 78 91019 6 12 1118 54 3121716 15 1413It can be verified that the sum of the numbers on the diagonals is 101.What is the sum of the numbers on the diagonals in a 1001 by 100 阅读全文