Let n be a positive integer such that 3 < n < 9. Let T be the set of all points with positive integer coordinates (x,y) in the plane for which the inequality x+y < n holds. Every point (x,y) of T is associated with the last digit of |p.x^2+q.y^2+p|, where p and q are integers. Two points of T are called neighbouring, if they lie on the coordinate axes or on lines parallel to them, and there are no other points of T between them.
Write a programme that
a) inputs values of variables n, p and q;
b) prints out nicely the coordinates of points belonging to T
and their associated digits, according to the above defined correspondence.
c) finds and prints out the arithmetic mean of all n-digit
decimal numbers a_0a_1a_2...a_(n-1),
that have digits a_0, a_1, ..., a_(n-1)
satisfying the following conditions:
- every digit a_i is associated with a point
of T according to the above given definition;
- for any two digits a_i and a_(i+1),
i = 0, 1, 2, ..., n-2, their corresponding points
t_i and t_(i+1) are neighbouring;
- a_0 is associated with (0,0);
- a_(n-1) is associated with point
(x,y), such that x+y=n-1.
d) for an input value of n, your programme computes and prints
out the number of points belonging to T and the number of all
the n-digit numbers, defined in c).
Write a programme, that on given values of integer variable n and real variable x, computes the value of:
x
A = ------------------------------------
x
1 + -----------------------------
x
2
+ -----------------------
x
3
+ ----------------
.
..
.. x
(n-1)
+ -----
n
+ x
Determine the value of N which will be printed after running the following programme:
(FORTRAN)
N=0
X=-999
10 X=X+1
IF(X-4)**2.GE.49)N=N+1
IF(X.LT.999)GO TO 10
WRITE(3,20)N
20 FORMAT(I6)
STOP
END
(BASIC)
1 N=0
5 X=-999
10 X=X+1
15 IF(X-1)^2>=49 THEN N=N+1
20 IF X<999 THEN GO TO 10
25 PRINT N
30 END
Given numbers a_1, a_2, ..., a_{2n}, n>=1, satisfying inequalities: 0 < a_1 < a_2 < a_3 < ... < a_{2n-1} < a_{2n}. Write a programme, that computes the least possible sum of n products of pairs a_i a_j (i<>j), being participating exactly once all of the 2n numbers.
Example: One possible sum is a_1a_2 + a_3a_4 + a_5a_6 + ... + a_{2n-1}a+{2n}.
Running the below given programme we get a sequence of numbers: 4, 9, 18. Which were the input data?
(FORTRAN)
INTEGER X(3), A(3), S
DO 10 I=1,3
X(I)=I-1
10 READ(1,20)A(I)
20 FORMAT(I5)
DO 40 N=1,3
S=0
DO 30 I=1,3
30 S=S*X(N)+A(I)
40 WRITE(3,50)S
50 FORMAT(I5)
STOP
END
(BASIC)
5 DIM X%(2), A%(2)
10 FOR I=0 TO 2
15 X%(I)=I
20 INPUT A%(I)
25 NEXT I
30 FOR N=0 TO 2
35 S%=0
40 FOR I=0 TO 2
45 S%=S%*X%(N)+A%(I)
50 NEXT I
55 PRINT S%
60 NEXT N
65 END
Consider the table for bitwise addition XOR (exclusive OR):
XOR | 0 1
----------
0 | 0 1
1 | 1 0
An example:
10010101
XOR
11001011
--------
01011110
Let variables A and B have values 10011011 and 11001101, respectively. Using only operation "=" (assignment) and XOR, exchange the values of A and B without applying any other auxiliary variables.
"Find some errors" in the programme:
(FORTRAN)
READ(1,5)X,Y,Z
5 FORMAT(3F5.2)
IF(X-Z)30,60,10
10 IF(X-Z)30,60,20
20 AMX=X
30 IF(Y-Z)50,60,40
40 AMX=Y
50 AMX=Z
60 WRITE(3,70) AXM
70 FORMAT(F6.2)
STOP
END
(BASIC)
5 INPUT X,Y,Z
10 IF X<Y GO TO 35
15 IF X=Y GO TO 55
20 IF X<Z GO TO 35
25 IF X=Z GO TO 55
30 AMX=X
35 IF Y<Z GO TO 50
40 IF Y=Z GO TO 55
45 AMX=Y
50 AMX=Z
55 PRINT AMX
60 END