Merge pull request #1 from pmpknu/p19

Add date utility functions, solutions and inline tests to p19

p19/.gitignore

@@ -0,0 +1,29 @@
+*.annot
+*.cmo
+*.cma
+*.cmi
+*.a
+*.o
+*.cmx
+*.cmxs
+*.cmxa
+
+# ocamlbuild working directory
+_build/
+
+# ocamlbuild targets
+*.byte
+*.native
+
+# oasis generated files
+setup.data
+setup.log
+
+# Merlin configuring file for Vim and Emacs
+.merlin
+
+# Dune generated files
+*.install
+
+# Local OPAM switch
+_opam/

p19/.ocamlformat

@@ -0,0 +1,2 @@
+profile = janestreet
+version = 0.26.2

p19/bin/dune

@@ -0,0 +1,4 @@
+(executable
+ (public_name p19)
+ (name main)
+ (libraries p19_lib))

p19/bin/main.ml

@@ -0,0 +1 @@
+let () = print_endline "Hello, World!"

p19/dune

@@ -0,0 +1,6 @@
+(rule
+ (alias lint)
+ (action
+  (progn
+   (echo "Running zanuda on OCaml files...")
+   (run bash -c "zanuda lib/*.ml"))))

p19/dune-project

@@ -0,0 +1,22 @@
+(lang dune 3.16)
+
+(name p19)
+
+(generate_opam_files true)
+
+(source
+ (github pmpknu/fp-lab1))
+
+(authors "Dan Gorlyakov")
+
+
+(license MIT)
+
+; (documentation https://url/to/documentation)
+
+(package
+ (name p19)
+ (synopsis "fp lab1")
+ (description "two tasks for the first lab for fp course at itmo")
+ (depends ocaml dune)
+)

p19/lib/date.ml

@@ -0,0 +1,32 @@
+let is_leap year = (year mod 4 = 0 && year mod 100 <> 0) || year mod 400 = 0
+
+let%test "is_leap for leap year 2000" = is_leap 2000 = true
+let%test "is_leap for leap year 2020" = is_leap 2020 = true
+let%test "is_leap for non-leap year 1900" = is_leap 1900 = false
+let%test "is_leap for non-leap year 2023" = is_leap 2023 = false
+
+let days_in_month year month =
+  match month with
+  | 1 | 3 | 5 | 7 | 8 | 10 | 12 -> 31
+  | 4 | 6 | 9 | 11 -> 30
+  | 2 -> if is_leap year then 29 else 28
+  | _ -> failwith "Invalid month"
+;;
+
+let%test "days_in_month for February in leap year" = days_in_month 2020 2 = 29
+let%test "days_in_month for February in non-leap year" = days_in_month 2021 2 = 28
+let%test "days_in_month for January" = days_in_month 2021 1 = 31
+let%test "days_in_month for April" = days_in_month 2021 4 = 30
+
+let zellers_congruence year month day =
+  let year, month = if month < 3 then year - 1, month + 12 else year, month in
+  let k = year mod 100 in
+  let j = year / 100 in
+  let f = day + (13 * (month + 1) / 5) + k + (k / 4) + (j / 4) - (2 * j) in
+  ((f mod 7) + 7) mod 7
+;;
+
+let%test "zellers_congruence for 1 Jan 1900 (Monday)" = zellers_congruence 1900 1 1 = 2
+let%test "zellers_congruence for 1 Jan 2000 (Saturday)" = zellers_congruence 2000 1 1 = 0
+let%test "zellers_congruence for 1 Mar 2021 (Monday)" = zellers_congruence 2021 2 28 = 1
+let%test "zellers_congruence for 31 Dec 1999 (Friday)" = zellers_congruence 1999 12 31 = 6

p19/lib/date.mli

@@ -0,0 +1,2 @@
+val days_in_month : int -> int -> int
+val zellers_congruence : int -> int -> int -> int

p19/lib/dune

@@ -0,0 +1,7 @@
+(library
+ (name p19_lib)
+ (modules date tailrec rec map iterative module)
+ (inline_tests
+  (flags (-verbose)))
+ (preprocess
+  (pps ppx_inline_test)))

p19/lib/iterative.ml

@@ -0,0 +1,13 @@
+open Date
+
+let count_sundays start_year end_year =
+  let count = ref 0 in
+  for year = start_year to end_year do
+    for month = 1 to 12 do
+      if zellers_congruence year month 1 = 0 then incr count
+    done
+  done;
+  !count
+;;
+
+let%test _ = count_sundays 1901 2000 = 171

p19/lib/map.ml

@@ -0,0 +1,13 @@
+open Date
+
+let count_sundays start_year end_year =
+  let years = List.init (end_year - start_year + 1) (fun i -> start_year + i) in
+  let aux year =
+    let months = List.init 12 (fun m -> m + 1) in
+    let map_filter month = if zellers_congruence year month 1 = 0 then 1 else 0 in
+    List.fold_left ( + ) 0 (List.map map_filter months)
+  in
+  List.fold_left (fun acc year -> acc + aux year) 0 years
+;;
+
+let%test _ = count_sundays 1901 2000 = 171

p19/lib/module.ml

@@ -0,0 +1,12 @@
+open Date
+
+let count_sundays start_year end_year =
+  let years = List.init (end_year - start_year + 1) (fun i -> start_year + i) in
+  let aux year =
+    let months = List.init 12 (fun m -> m + 1) in
+    List.filter (fun month -> zellers_congruence year month 1 = 0) months |> List.length
+  in
+  List.fold_left (fun acc year -> acc + aux year) 0 years
+;;
+
+let%test _ = count_sundays 1901 2000 = 171

p19/lib/rec.ml

@@ -0,0 +1,15 @@
+open Date
+
+let rec count_sundays year month day_of_week =
+  if year > 2000
+  then 0
+  else (
+    let new_count = if day_of_week = 0 then 1 else 0 in
+    let days_this_month = days_in_month year month in
+    let next_day_of_week = (day_of_week + days_this_month) mod 7 in
+    if month == 12
+    then new_count + count_sundays (year + 1) 1 next_day_of_week
+    else new_count + count_sundays year (month + 1) next_day_of_week)
+;;
+
+let%test _ = count_sundays 1901 1 2 = 171

p19/lib/tailrec.ml

@@ -0,0 +1,15 @@
+open Date
+
+let rec count_sundays year month day_of_week count =
+  if year > 2000
+  then count
+  else (
+    let new_count = if day_of_week = 0 then count + 1 else count in
+    let days_this_month = days_in_month year month in
+    let next_day_of_week = (day_of_week + days_this_month) mod 7 in
+    if month == 12
+    then count_sundays (year + 1) 1 next_day_of_week new_count
+    else count_sundays year (month + 1) next_day_of_week new_count)
+;;
+
+let%test _ = count_sundays 1901 1 2 0 = 171

p19/p19.opam

@@ -0,0 +1,28 @@
+# This file is generated by dune, edit dune-project instead
+opam-version: "2.0"
+synopsis: "fp lab1"
+description: "two tasks for the first lab for fp course at itmo"
+authors: ["Dan Gorlyakov"]
+license: "MIT"
+homepage: "https://github.com/pmpknu/fp-lab1"
+bug-reports: "https://github.com/pmpknu/fp-lab1/issues"
+depends: [
+  "ocaml"
+  "dune" {>= "3.16"}
+  "odoc" {with-doc}
+]
+build: [
+  ["dune" "subst"] {dev}
+  [
+    "dune"
+    "build"
+    "-p"
+    name
+    "-j"
+    jobs
+    "@install"
+    "@runtest" {with-test}
+    "@doc" {with-doc}
+  ]
+]
+dev-repo: "git+https://github.com/pmpknu/fp-lab1.git"

p19/solution.py

@@ -0,0 +1,11 @@
+from datetime import datetime, timedelta
+
+sundays_count = 0
+
+for year in range(1901, 2001):
+    for month in range(1, 13):
+        first_day = datetime(year, month, 1)
+        if first_day.weekday() == 6:
+            sundays_count += 1
+
+print(sundays_count)