! 10.7.f90
! 2025-6-28
! $Id: 10.7.f90 1.1 2025/06/28 11:50:32 s Exp $

program a
! 現在価格 s
! 先渡価格 f
! クーポン c
! 利子率 r1
! 利子率 r2
! キャッシュフロー流列 x
! 割引係数配列 d
! 現在価値 pv
implicit none
integer :: m
real    :: c, f, pv, r1, r2, s
real    :: d(3), x(3), xd(3)

! main
call input(s, c, f, m, r1, r2, x)
call calculation(m, r1, r2, d, x, xd, pv)
call output(s, c, f, m, r1, r2, x, d, xd, pv)

contains
subroutine input(s, c, f, m, r1, r2, x)
    integer :: m
    real :: x(3), x1(3), x2(3), x3(3)
    real :: s, c, f, r1, r2
    s = 920.0
    c =  80.0
    f = 940.0
    m =   2
    r1 = 0.07
    r2 = 0.08
    x1 = [  -s, 0.0, 0.0] ! 初期支出
    x2 = [ 0.0,   c,   c] ! クーポン収入
    x3 = [ 0.0, 0.0,   f] ! 満期時収入
    x = x1 + x2 + x3
end subroutine input

subroutine calculation(m, r1, r2, d, x, xd, pv)
    integer :: m
    real :: d0, d1, d2, pv, r1, r2
    real :: x(3), d(3), xd(3)
    d0 = 1.0
    d1 = 1.0 / (1 + r1 / m)
    d2 = 1.0 / (1 + r2 / m) ** 2
    d  = [d0, d1, d2]
    xd = x * d
    pv = sum(xd)
end subroutine calculation

subroutine output(s, c, f, m, r1, r2, x, d, xd, pv)
    integer :: m
    real :: s, c, f, r1, r2, pv
    real :: x(3), d(3), xd(3)
    print *, "10.7.js"
    print *, "s",  s
    print *, "c",  c
    print *, "f",  f
    print *, "r1", r1
    print *, "r2", r2
    print *, "m",  m
    print *, "x",  x
    print *, "d",  d
    print *, "xd", xd
    print *, "pv", pv
end subroutine output
end program a