Hi all, I am doing the Euler project exercise number 8
I don’t need help with the code, but here it is anyways :
PROGRAM pr8
USE, INTRINSIC :: ISO_FORTRAN_ENV, ONLY: int64
IMPLICIT NONE
CHARACTER(len=1000) :: the_number
INTEGER(KIND=int64),ALLOCATABLE :: number_array_tmp(:),number_array_best(:)
INTEGER(KIND=int64) :: greatest_product,product_tmp,number_array_size,i,j
INTEGER(KIND=int64) :: array_pos,parser_stop_var
OPEN (UNIT=10,FILE='pr8_input.txt')
READ (10,*) the_number
CLOSE(10)
PRINT *, the_number
PRINT *, " "
WRITE(unit=*, FMT="(a)", ADVANCE="no") &
"Please enter the amount of numbers in a sequence "
READ *, number_array_size
ALLOCATE(number_array_tmp(number_array_size))
ALLOCATE(number_array_best(number_array_size))
array_pos = INT(1, KIND=int64)
parser_stop_var = number_array_size + array_pos
parser_stop_var = array_pos
greatest_product = 1
DO WHILE((array_pos+(number_array_size)) .LE. LEN(the_number, KIND=int64))
product_tmp = 1
DO i=1,number_array_size
READ(the_number(parser_stop_var:parser_stop_var),*)&
number_array_tmp(i)
parser_stop_var = parser_stop_var + INT(1, KIND=int64)
END DO
product_tmp = PRODUCT(number_array_tmp)
IF (product_tmp .GT. greatest_product) THEN
greatest_product = product_tmp
number_array_best = number_array_tmp
END IF
array_pos = array_pos + INT(1, KIND=int64)
parser_stop_var = array_pos
END DO
PRINT *, " "
PRINT *, "The greatest product is "
PRINT *, greatest_product
END PROGRAM pr8
Here is the input file :
7316717653133062491922511967442657474235534919493496983520312774506326239578318016984801869478851843858615607891129494954595017379583319528532088055111254069874715852386305071569329096329522744304355766896648950445244523161731856403098711121722383113622298934233803081353362766142828064444866452387493035890729629049156044077239071381051585930796086670172427121883998797908792274921901699720888093776657273330010533678812202354218097512545405947522435258490771167055601360483958644670632441572215539753697817977846174064955149290862569321978468622482839722413756570560574902614079729686524145351004748216637048440319989000889524345065854122758866688116427171479924442928230863465674813919123162824586178664583591245665294765456828489128831426076900422421902267105562632111110937054421750694165896040807198403850962455444362981230987879927244284909188845801561660979191338754992005240636899125607176060588611646710940507754100225698315520005593572972571636269561882670428252483600823257530420752963450
I would like to know if it is possible to turn this do loop into an implied do loop :
DO i=1,number_array_size
READ(the_number(parser_stop_var:parser_stop_var),*)&
number_array_tmp(i)
parser_stop_var = parser_stop_var + INT(1, KIND=int64)
END DO
Also, feel free to provide any suggestions on improving the code.