From ec3f5b379a298607b5bc958d867764967495d1b7 Mon Sep 17 00:00:00 2001
From: William Ball <wball1@swarthmore.edu>
Date: Sun, 2 Aug 2020 01:22:39 -0700
Subject: [PATCH] memory light

---
 fortran/fourthfree.f90      | 144 ++++++++++++++++++++++++++++++++++++
 rust/fourthfree/log         |  22 ++++++
 rust/fourthfree/src/main.rs |   2 +-
 3 files changed, 167 insertions(+), 1 deletion(-)
 create mode 100644 fortran/fourthfree.f90
 create mode 100644 rust/fourthfree/log

diff --git a/fortran/fourthfree.f90 b/fortran/fourthfree.f90
new file mode 100644
index 0000000..6c6ef5d
--- /dev/null
+++ b/fortran/fourthfree.f90
@@ -0,0 +1,144 @@
+program test
+implicit none
+    1   format(20i10)
+
+    integer (kind = 8), parameter :: base = 2
+    integer (kind = 8), dimension (:), allocatable :: ls, temp1, temp2
+    double precision :: S
+    integer (kind = 8) :: i
+
+    allocate(ls(1))
+    ls = (/1/)
+    S = 0
+
+    do i = 1, 63
+        S = S + (real(size(ls)) / real(2 ** i))
+        print *, "ITERATION", i
+        print *, "NUMBER   ", size(ls)
+        print *, "SUM      ", S
+        print *, ""
+        call flush()
+        temp1 = next(ls)
+        temp2 = ls
+        ls = temp1
+        deallocate(temp2)
+    end do
+    
+
+contains
+
+function is_fourth_free (x)
+
+    integer (kind = 8), intent (in) :: x
+    integer (kind = 8)              :: i
+    logical :: is_fourth_free
+
+    i = 2
+    do while (i * i * i * i <= x)
+        if (mod(x, i * i * i * i) == 0) then
+            is_fourth_free = .false.
+            return
+        end if
+        i = i + 1
+    end do
+    is_fourth_free = .true.
+
+end function is_fourth_free
+
+function is_square_free (x)
+
+    integer (kind = 8), intent (in) :: x
+    integer (kind = 8)              :: i
+    logical :: is_square_free
+
+    i = 2
+    do while (i * i <= x)
+        if (mod(x, i * i) == 0) then
+            is_square_free = .false.
+            return
+        end if
+        i = i + 1
+    end do
+    is_square_free = .true.
+
+end function is_square_free
+
+function is_prime (x)
+
+    integer (kind = 8), intent (in) :: x
+    integer (kind = 8)              :: i
+    logical :: is_prime
+
+    if (x < 2 .or. mod(x, 2) == 0) then
+        is_prime = .false.
+        return
+    end if
+
+    i = 3
+    do while (i * i <= x)
+        if (mod(x, i) == 0) then
+            is_prime = .false.
+            return
+        end if
+        i = i + 2
+    end do
+    is_prime = .true.
+
+end function is_prime
+
+function step (x)
+implicit none
+
+    integer (kind = 8), intent (in)                :: x
+    integer (kind = 8)                             :: i, t, count
+    integer (kind = 8), dimension (:), allocatable :: step
+    integer (kind = 8), dimension (base)           :: temp
+
+    count = 0
+
+    do i = 0, base - 1
+        t = x * base + i
+        if (is_fourth_free(t)) then
+            count = count + 1
+            temp(count) = t
+        end if
+    end do
+
+    allocate(step(count))
+
+    do i = 1, count
+        step(i) = temp(i)
+    end do
+
+end function step
+
+function next (ls)
+    1   format(20i10)
+
+    integer (kind = 8), dimension (:), allocatable, intent (in) :: ls
+    integer (kind = 8), dimension (:), allocatable :: temp, temp2, next
+    integer :: s, i, j, count
+
+    count = 0
+    s = size(ls)
+    allocate(temp(s * base))
+
+    do i = 1, s
+        temp2 = step(ls(i))
+        do j = 1, size(temp2)
+            temp(j + count) = temp2(j)
+        end do
+        count = count + size(temp2)
+        deallocate(temp2)
+    end do
+
+    allocate(next(count))
+    do i = 1, count
+        next(i) = temp(i)
+    end do
+
+    deallocate(temp)
+
+end function next
+
+end program test
diff --git a/rust/fourthfree/log b/rust/fourthfree/log
new file mode 100644
index 0000000..d737a92
--- /dev/null
+++ b/rust/fourthfree/log
@@ -0,0 +1,22 @@
+1	1	0.5
+2	2	1
+3	4	1.5
+4	8	2
+5	15	2.46875
+6	29	2.921875
+7	55	3.3515625
+8	105	3.76171875
+9	201	4.154296875
+10	383	4.5283203125
+11	733	4.88623046875
+12	1401	5.228271484375
+13	2678	5.55517578125
+14	5119	5.86761474609375
+15	9784	6.16619873046875
+16	18701	6.4515533447265625
+17	35738	6.724212646484375
+18	68307	6.984783172607422
+19	130554	7.233795166015625
+20	249518	7.47175407409668
+21	476910	7.699162483215332
+22	911526	7.916487216949463
diff --git a/rust/fourthfree/src/main.rs b/rust/fourthfree/src/main.rs
index e30a2d0..6a0993b 100644
--- a/rust/fourthfree/src/main.rs
+++ b/rust/fourthfree/src/main.rs
@@ -3,7 +3,7 @@ use rayon::prelude::*;
 // use std::thread;
 
 // const NUM_THREADS: usize = 12;
-const BASE: u64 = 10;
+const BASE: u64 = 2;
 
 fn is_fourth_free(x: &u64) -> bool {
     let mut i = 2;