Seventh session (16) Blue Bridge Cup Java Group B final real title

1. Angry Birds (fill in the blanks)
Planet X Angry Birds like to hit the train!

A straight track, 1000 meters between the two trains.
The two trains (which may be called A and b) travel at 10 m/s per hour.

Angry Birds from a car, speed 50 m/s, crashed into B car,
Then go back to hit a car, and then back to hit B car, so reciprocating ....
The two trains are parked 1 metres apart.

Q: How many times has the angry bird hit the B car?

Note: You need to submit an integer (indicating the number of times you crashed the B car), do not fill in any other content.

1   Public classOne {2     //A, B's position A, B's size relative to A's starting point, the bird's speed is 50,a, B's speed all is ten3      Public Static Doublesum=0;//sum used for the number of collisions between birds and b during the specified period4      Public Static voidFunb (DoubleADoubleb) {//in the distance A, b birds hit B by a5         if(b-a<=1){6 System.out.println (sum);7             return;8         }9         DoubleTime= (b-a)/(50+10);//the time when the bird and B collided during the distance of A and BTenA=a+10*time;//the position of a after hitting OneB=b-10*time;//the position of B after the crash Asum++; -Funa (A, b);//The bird turns to a when the bird and B collide. -         return; the     } -      -      Public Static voidFuna (DoubleADoubleb) {//birds Fly by B to a -         if(b-a<1) {//if the distance between the bird and the B is less than 1 after the collision, then sum-- +sum--; - System.out.println (sum); +         } A         DoubleTime= (b-a)/(50+10); atA=a+10*time;//the position of a after hitting -B=b-10*time;//the position of B after the crash - Funb (A, b); -         return; -     } -      Public Static voidMain (String args[]) { in         Doublea=0,b=1000; - Funb (A, b); to     } +}

Angry Birds (two recursive functions)

The answer is: 9

2. Anti-Magic side (fill in the blanks)
The ancient books of our country record very early

2 9 4
7 5 3
6 1 8
This is a third-order magic side. Each row and the number on the diagonal are added equally.

Consider the opposite problem below.
It is not possible to fill nine Gongge with 1~9 numbers.
So that the numbers on each diagonal of each row are not equal to each other?

This should be able to do.
Like what:
9 1 2
8 4 3
7 5 6

Your task is to search all third-order anti-magic squares. and count the total number of species.
Rotate or mirror the same type.

Like what:
9 1 2
8 4 3
7 5 6

7 8 9
5 4 1
6 3 2

2 1 9
3 4 8
6 5 7
are counted as the same situation.

Please submit the number of third-order anti-magic side altogether. This is an integer, do not fill in any superfluous content.

1  Public classMain {2      Public Static intsum = 0;//counter3 4      Public Static voidFunintA[],intN) {5         if(n = = 9) {6 text (a);7             return;8}Else {9              for(inti = n; I < 9; i++) {//N Behind theTen                 inttemp =A[i]; OneA[i] =A[n]; AA[n] =temp; -Fun (A, n + 1); -                 intTamp =A[i]; theA[i] =A[n]; -A[n] =tamp; -             } -         } +     } -  +      Public Static voidTextinta[]) { A         intL1 = a[0] + a[1] + a[2]; at         intL2 = A[3] + a[4] + a[5]; -         intL3 = A[6] + a[7] + a[8]; -         intS1 = a[0] + a[3] + a[6]; -         intS2 = a[1] + a[4] + a[7]; -         intS3 = A[2] + a[5] + a[8]; -         intX1 = a[0] + a[4] + a[8]; in         intx2 = a[2] + a[4] + a[6]; -         if(L1! = L2 && L1! = L3 && L1! = S1 && L1! = S2 && L1! = S3 && L1! = x1 && L 1! =x2) to             if(L2! = L3 && L2! = S1 && L2! = S2 && L2! = S3 && L2! = x1 && L2! =x2) +                 if(L3! = S1 && L3! = S2 && L3! = S3 && L3! = x1 && L3! =x2) -                     if(S1! = S2 && S1! = S3 && S1! = x1 && S1! =x2) the                         if(S2! = S3 && s2! = x1 && S2! =x2) *                             if(S3! = x1 && S3! =x2) $                                 if(X1! =x2)Panax Notoginsengsum++; -     } the      Public Static voidMain (string[] args) { +         inta[]={1,2,3,4,5,6,7,8,9};  AFun (a,0);  theSystem.out.print (SUM/8);  +     } -}

third-order anti-magic Square (Recursive)

The answer is: 3120

Seventh session (16) Blue Bridge Cup Java Group B final real title