POJ 1006 Biorhythms

POJ 1003,1004,1005 is relatively simple and soon solved. There is a small episode, just beginning to do not understand the ACM, the most recent submission of the problem is the runtime Error, the beginning I thought it was timed out, on the one hand I suspect is not Java run too slow, and then to understand that some international competitions recommended Java, that the Java itself is not slow. On the other hand I suspect that my program is too bad, each time is very good time-consuming, so every time the runtime error problem to optimize the code, but how to optimize or not. Finally, the POJ1005 online code affixed to the AC, but I still do not, this time only to find the culprit is when I submit always with the package name (of course, sometimes manually).

POJ 1006 This topic although I can submit through, but my method more calculate brute force hack.

Import Java.util.scanner;public class Main {public static void main (string[] args) {Scanner Scanner = new Scanner (system.in ); for (int j=1; j<integer.max_value; J + +) {int p = scanner.nextint ()% 23;int e = scanner.nextint ()% 28;int i = scanner. Nextint ()% 33;int d = scanner.nextint (); if (p==-1 && e==-1 && i==-1 && d==-1) return;for (int numbe r=0; number<=21252+d; {if (p = = number%) {if (e = = number%) {if (i = = number%) {if (number-d <= 0) Number + = 21252; SYSTEM.OUT.PRINTLN ("Case" +j+ ": The next triple peak occurs in" + (number-d) + "days."); break;} Elsenumber + = 23*28;} else number + = 23;} else number + +;}}}}

The key to the problem is to abstract the essence from the complex phenomenon, that is, to transform the topic into a mathematical problem. The difficulty of this problem is the mathematical problem behind--the Chinese remainder theorem.

This topic is known as number% at p,number = e,number% = I

Make 33*28*a 23 to 1, 5544 = 33*28*6

Make 23*33*b 23 to 1, 14421 = 23*33*19

Make 23*28*c 33 to 1, 1288 = 23*28*2

Therefore there is (5544*p + 14421*e + 1288*i)% LCM (at a total of.) = number

Also due to 23,28,33 coprime, the LCM (23, 28, 33) = 21252. So number = (5544*p + 14421*e + 1288*i)% 21252, the request is number-d, the subject is the smallest integer solution, to avoid n is negative need to add 21252 when the number-d<=0.

POJ 1006 Biorhythms