ProblemSetters · ya-developer · Jul 17, 2026 · Jun 30, 2026
diff --git a/.editorconfig b/.editorconfig
@@ -0,0 +1,18 @@
+# Editor configuration, see https://editorconfig.org
+root = true
+
+[*]
+charset = utf-8
+end_of_line = lf
+indent_size = 2
+indent_style = space
+insert_final_newline = true
+max_line_length = 1234567890
+trim_trailing_whitespace = true
+
+[Makefile.{blackbox,workflow}]
+indent_size = 4
+indent_style = tab
+
+[*.md]
+indent_size = 4
diff --git a/Makefile.blackbox b/Makefile.blackbox
@@ -2,94 +2,105 @@
 override blackbox/:=*
 
 ifeq ($(origin .FEATURES),undefined)
-  $(error `make` executable version "$(MAKE_VERSION)" is not supported. GNU Make 3.82 or above is required)
-endif
-
-override SHELL:=/bin/bash
-
-ifneq ($(value SHELL),$(shell echo $$BASH))
-  $(error current shell executable is not supported. GNU Bash 4.3 or above is required)
+  $(error `make` executable version `$(MAKE_VERSION)` is not supported. GNU Make 4.3 or above is required)
 endif
 
 ifeq ($(words $(MAKEFILE_LIST)),1)
-  $(error `Makefile.blackbox` should be included, direct usage is not allowed)
+  $(error `Makefile` should be included, direct usage is not allowed)
 endif
 
-BLACKBOX_FLAG__DEBUG_MODE:=no
-BLACKBOX_FLAG__STEP_PROVISION:=yes
-BLACKBOX_FLAG__STEP_BUILD:=yes
-BLACKBOX_FLAG__STEP_EVALUATE:=yes
+ifeq ($(shell which gawk),)
+  $(error `gawk` executable is required)
+endif
 
-ifneq ($(BLACKBOX_DIR),$(abspath $(dir $(lastword $(MAKEFILE_LIST)))))
-  $(error `BLACKBOX_DIR` configuration is not valid)
+ifeq ($(shell which vagrant),)
+  $(error `vagrant` executable is required)
 endif
 
-BLACKBOX_HOST:=blackbox-$(shell basename $(PWD) | cut -c 1-36)
-BLACKBOX_SPAWN:=blackbox-spawn-$(shell basename $(PWD) | cut -c 1-36)
-BLACKBOX_USER?=$(shell id -u):$(shell id -g)
-BLACKBOX_USER_NAME:=ubuntu
-BLACKBOX_USER_HOME:=/home/$(BLACKBOX_USER_NAME)
-BLACKBOX_USER_QUESTION_DIR=$(BLACKBOX_USER_HOME)/$(shell basename $(call blackbox/pwd))
-BLACKBOX_VERSION:=2404
+override SHELL:=/usr/bin/env bash -e +o pipefail
 
-BLACKBOX_AWS_DEFAULT_REGION:="us-east-1"
-BLACKBOX_AWS_ACCESS_KEY_ID:=$(shell base64 -d <(base64 -d <<<"UVV0SlFWSTJUemRIU2s1WVdVSk1RVXBGTlRNSwo="))
-BLACKBOX_AWS_SECRET_ACCESS_KEY:=$(shell base64 -d <(base64 -d <<<"UVVaNFZUVXJWMEZoYml0eWVWUnpVSGhuY1ZWTk56VXlPVlp5Umt0Q1JFTkxRMHBFY3pKSFV3bz0K"))
+ifeq ($(shell echo $$BASH),)
+  $(error current shell executable is not supported. GNU Bash 5.1 or above is required)
+endif
 
-define blackbox/pwd=
-$(abspath $(dir $(firstword $(MAKEFILE_LIST)))/$(1))
-endef
+override blackbox/debug:=$(if $(filter debug,$(MAKECMDGOALS)),yes,no)
+override blackbox/host/blackbox/path:=$(abspath $(dir $(lastword $(MAKEFILE_LIST))))
+override blackbox/host/question/path:=$(abspath $(dir $(firstword $(MAKEFILE_LIST))))
+override blackbox/spawn/blackbox/path:=/blackbox
+override blackbox/spawn/question/path:=/question
+override blackbox/spawn/id:=blackbox-$(shell basename $(blackbox/host/question/path) | cut --characters="1-36")
+override blackbox/spawn/cpu/limit=$(if $(filter yes,$(blackbox/debug)),$(shell nproc),4)
+override blackbox/spawn/memory/limit=$(if $(filter yes,$(blackbox/debug)),$(shell awk '/MemTotal/ { printf "%.0f\n", $$2 / 1024 }' /proc/meminfo),4096)
+override blackbox/spawn/disk/limit:=20G
+override blackbox/spawn/username:=ubuntu
+
+export VAGRANT_DEBUG=$(blackbox/debug)
+export VAGRANT_HOST_BLACKBOX_PATH=$(blackbox/host/blackbox/path)
+export VAGRANT_HOST_QUESTION_PATH=$(blackbox/host/question/path)
+export VAGRANT_SPAWN_ID=$(blackbox/spawn/id)
+export VAGRANT_SPAWN_BLACKBOX_PATH=$(blackbox/spawn/blackbox/path)
+export VAGRANT_SPAWN_QUESTION_PATH=$(blackbox/spawn/question/path)
+export VAGRANT_CPU_LIMIT=$(blackbox/spawn/cpu/limit)
+export VAGRANT_MEMORY_LIMIT=$(blackbox/spawn/memory/limit)
+export VAGRANT_VAGRANTFILE=$(blackbox/host/blackbox/path)/Vagrantfile
+
+BLACKBOX_FLAG__DEBUG_MODE=$(blackbox/debug)
+BLACKBOX_FLAG__STEP_PROVISION:=yes
+BLACKBOX_FLAG__STEP_BUILD:=yes
+BLACKBOX_FLAG__STEP_EVALUATE:=yes
 
 debug: ;@:
-	$(eval BLACKBOX_FLAG__DEBUG_MODE:=yes)
-	$(foreach variable,BLACKBOX_FLAG__DEBUG_MODE BLACKBOX_FLAG__STEP_PROVISION BLACKBOX_FLAG__STEP_BUILD BLACKBOX_FLAG__STEP_EVALUATE,$(info $(shell printf "\033[0;37m%s = %s\033[0m" "$(variable)" "$($(variable))")))
+	$(foreach variable,$(filter blackbox/%,$(sort $(.VARIABLES))),$(info $(shell printf "\033[0;37m%s = %s\033[0m" "$(variable)" "$($(variable))")))
 	$(info $(shell printf "\033[0;37m%s\033[0m" \\))
-	$(foreach variable,$(filter-out BLACKBOX_FLAG__%,$(filter BLACKBOX_%,$(sort $(.VARIABLES)))),$(info $(shell printf "\033[0;37m%s = %s\033[0m" "$(variable)" "$($(variable))")))
+	$(foreach variable,$(filter VAGRANT_%,$(sort $(.VARIABLES))),$(info $(shell printf "\033[0;37m%s = %s\033[0m" "$(variable)" "$($(variable))")))
+	$(info $(shell printf "\033[0;37m%s\033[0m" \\))
+	$(foreach variable,BLACKBOX_FLAG__DEBUG_MODE BLACKBOX_FLAG__STEP_PROVISION BLACKBOX_FLAG__STEP_BUILD BLACKBOX_FLAG__STEP_EVALUATE,$(info $(shell printf "\033[0;37m%s = %s\033[0m" "$(variable)" "$($(variable))")))
 	$(if $(and $(filter-out $(words $(MAKECMDGOALS)),0),$(filter-out $(words $(MAKECMDGOALS)),1)),$(info $(shell printf "\033[0;37m%s\033[0m" --)))
 
-all: uninstall install setup solve check
+all: uninstall install setup save solve check restore check
+
+up: uninstall install setup save
+
+100: restore solve check
+
+0: restore check
 
 install:
-	docker login --username AWS --password-stdin 134148934511.dkr.ecr.us-east-1.amazonaws.com < <(docker run -it --env="AWS_DEFAULT_REGION=$(BLACKBOX_AWS_DEFAULT_REGION)" --env="AWS_ACCESS_KEY_ID=$(BLACKBOX_AWS_ACCESS_KEY_ID)" --env="AWS_SECRET_ACCESS_KEY=$(BLACKBOX_AWS_SECRET_ACCESS_KEY)" --rm amazon/aws-cli:2.11.25 ecr get-login-password)
-	cat <(echo FROM 134148934511.dkr.ecr.us-east-1.amazonaws.com/hr/blackbox_2404:abstract) <(echo RUN groupadd docker) | docker buildx build --build-arg="BLACKBOX_USER=$(BLACKBOX_USER)" --build-arg="BLACKBOX_USER_NAME=$(BLACKBOX_USER_NAME)" --build-arg="BLACKBOX_USER_HOME=$(BLACKBOX_USER_HOME)" --build-arg="BLACKBOX_VERSION=$(BLACKBOX_VERSION)" --network="host" --progress="plain" --tag="blackbox:$(BLACKBOX_HOST)" -
-	docker run -di --group-add docker --hostname="blackbox" --name="$(BLACKBOX_HOST)" --privileged --cgroupns=host $(if $(filter debug,$(MAKECMDGOALS)),--volume="$(BLACKBOX_DIR):/blackbox:ro") --volume="$(call blackbox/pwd)/setup.sh:$(BLACKBOX_USER_HOME)/setup.sh:ro" --volume="$(call blackbox/pwd)/check.sh:$(BLACKBOX_USER_HOME)/check.sh:ro" --volume="$(call blackbox/pwd)/solve.sh:$(BLACKBOX_USER_HOME)/solve.sh:ro" --volume="$(call blackbox/pwd)/evaluate.sh:$(BLACKBOX_USER_HOME)/evaluate.sh:ro" blackbox:$(BLACKBOX_HOST) >/dev/null
+	vagrant --no-color up $(blackbox/spawn/id)
+	vagrant --no-color snapshot save -f $(blackbox/spawn/id) install
+
+reinstall:
+	vagrant --no-color snapshot restore $(blackbox/spawn/id) install
 
 setup:
-	docker exec -it --env="BLACKBOX_FLAG__DEBUG_MODE=$(BLACKBOX_FLAG__DEBUG_MODE)" --env="BLACKBOX_FLAG__STEP_PROVISION=$(BLACKBOX_FLAG__STEP_PROVISION)" --env="BLACKBOX_USER_QUESTION_DIR=$(BLACKBOX_USER_QUESTION_DIR)" --env="BLACKBOX_VERSION=$(BLACKBOX_VERSION)" $(BLACKBOX_HOST) $(SHELL) setup.sh
+	vagrant ssh --command="sudo BLACKBOX_FLAG__DEBUG_MODE=$(BLACKBOX_FLAG__DEBUG_MODE) bash $(blackbox/spawn/question/path)/setup.sh" $(blackbox/spawn/id)
 
-solve:
-	docker exec -it --user="$(BLACKBOX_USER)" $(BLACKBOX_HOST) $(SHELL) solve.sh
-	docker exec -it -w $(BLACKBOX_USER_QUESTION_DIR) --user="$(BLACKBOX_USER)" $(BLACKBOX_HOST) $(SHELL) -c "source /blackbox/blackbox &>/dev/null; solve"
+save:
+	vagrant --no-color snapshot save -f $(blackbox/spawn/id) latest
 
-evaluate:
-	docker exec -it $(BLACKBOX_HOST) $(SHELL) evaluate.sh
+restore:
+	vagrant --no-color snapshot restore $(blackbox/spawn/id) latest
+
+solve:
+	vagrant ssh --command="sudo bash $(blackbox/spawn/question/path)/solve.sh" $(blackbox/spawn/id)
 
 check:
-	docker exec -it --env="BLACKBOX_SPAWN=$(BLACKBOX_SPAWN)" --env="BLACKBOX_USER_QUESTION_DIR=$(BLACKBOX_USER_QUESTION_DIR)" --env="BLACKBOX_FLAG__DEBUG_MODE=$(BLACKBOX_FLAG__DEBUG_MODE)" --env="BLACKBOX_FLAG__STEP_PROVISION=$(BLACKBOX_FLAG__STEP_PROVISION)" --env="BLACKBOX_FLAG__STEP_BUILD=$(BLACKBOX_FLAG__STEP_BUILD)" --env="BLACKBOX_FLAG__STEP_EVALUATE=$(BLACKBOX_FLAG__STEP_EVALUATE)" --env="BLACKBOX_VERSION=$(BLACKBOX_VERSION)" $(BLACKBOX_HOST) $(SHELL) check.sh
+	vagrant ssh --command="sudo BLACKBOX_FLAG__DEBUG_MODE=$(BLACKBOX_FLAG__DEBUG_MODE) BLACKBOX_FLAG__STEP_PROVISION=$(BLACKBOX_FLAG__STEP_PROVISION) BLACKBOX_FLAG__STEP_BUILD=$(BLACKBOX_FLAG__STEP_BUILD) BLACKBOX_FLAG__STEP_EVALUATE=$(BLACKBOX_FLAG__STEP_EVALUATE) bash $(blackbox/spawn/question/path)/check.sh" $(blackbox/spawn/id) | tee >(awk '/Partial Credit/ { if (!reset) { reset = 1; next }; total_score += $$3; ok += ($$3 > 0); failed += ($$3 == 0) } END { printf("\n--\nSuccess: %d\nFail: %d\n\nTotal: %d\n--\n\nTotal Credit: %d\n", ok, failed, ok + failed, total_score) }')
 
 check\:evaluate:
-	$(MAKE) BLACKBOX_FLAG__STEP_PROVISION=no BLACKBOX_FLAG__STEP_BUILD=no BLACKBOX_FLAG__STEP_EVALUATE=yes check
+	$(eval BLACKBOX_FLAG__STEP_PROVISION:=no)
+	$(eval BLACKBOX_FLAG__STEP_BUILD:=no)
+	$(MAKE) check
 
 shell:
-	docker exec -it -w $(BLACKBOX_USER_QUESTION_DIR) --user="$(BLACKBOX_USER)" $(BLACKBOX_HOST) $(SHELL)
-
-hr:
-	cat <(xargs -r xdg-open 2>/dev/null < <(grep -o 'https://www.hackerrank.com.*' README.md))
-
-gh:
-	cat <(xargs -r xdg-open 2>/dev/null < <(grep -o 'https://github.com.*' README.md))
-
-shell\:spawn:
-	docker exec -it $(BLACKBOX_HOST) $(SHELL) -c "docker exec -it -w $(BLACKBOX_USER_QUESTION_DIR) $(BLACKBOX_SPAWN) $(SHELL)"
+	vagrant ssh $(blackbox/spawn/id) --command="sudo su - $(blackbox/spawn/username)"
 
 uninstall:
-	xargs -r docker rm -f >/dev/null < <(docker ps -aq -f "name=$(BLACKBOX_HOST)")
-	docker rmi blackbox:$(BLACKBOX_HOST) 2>/dev/null || true
+	vagrant destroy -f
+	rm -rf .vagrant
 
-prune:
-	xargs -r docker stop >/dev/null < <(docker ps -aq -f "name=blackbox-")
-	docker system prune -a --volumes
+gh:
+	grep -o "https://github.com.*" "$(blackbox/host/question/path)/README.md" | xargs -r xdg-open &>/dev/null
 
-ifeq ($(filter debug,$(MAKECMDGOALS)),)
-.SILENT:
-endif
+hr:
+	grep -o "https://www.hackerrank.com.*" "$(blackbox/host/question/path)/README.md" | xargs -r xdg-open &>/dev/null
diff --git a/Makefile.vagrant b/Makefile.vagrant
diff --git a/Vagrantfile b/Vagrantfile
@@ -1,11 +1,22 @@
 Vagrant.configure("2") do |config|
   config.vm.box = "bento/ubuntu-24.04"
   config.vm.hostname = "taskserver"
+
+  config.vm.define ENV["VAGRANT_SPAWN_ID"] do |machine|
+    config.vm.provider "virtualbox" do |vb|
+      vb.name = ENV["VAGRANT_SPAWN_ID"]
+      vb.cpus = ENV["VAGRANT_CPU_LIMIT"]
+      vb.memory = ENV["VAGRANT_MEMORY_LIMIT"]
+    end
+  end
+
   config.vm.synced_folder ".", "/vagrant", disabled: true
-  if ENV["BLACKBOX_FLAG__DEBUG_MODE"] == "yes"
-    config.vm.synced_folder ENV["BLACKBOX_DIR"], "/blackbox", mount_options: ["uid=0", "gid=0", "ro"]
+
+  if ENV["VAGRANT_DEBUG"] == "yes"
+    config.vm.synced_folder ENV["VAGRANT_HOST_BLACKBOX_PATH"], ENV["VAGRANT_SPAWN_BLACKBOX_PATH"], mount_options: ["uid=0", "gid=0", "ro"]
   end
-  config.vm.synced_folder ENV["BLACKBOX_HOST_TEST_DIR"], "/test", mount_options: ["uid=0", "gid=0", "ro"]
+
+  config.vm.synced_folder ENV["VAGRANT_HOST_QUESTION_PATH"], ENV["VAGRANT_SPAWN_QUESTION_PATH"], mount_options: ["uid=0", "gid=0", "ro"]
   config.vm.provision "shell", inline: <<-SHELL
     apt update && {
       DEBIAN_FRONTEND=noninteractive apt install -y unzip

diff --git a/blackbox b/blackbox
@@ -14,6 +14,8 @@
 # @set BLACKBOX_FLAG__STEP_BUILD type=enum<yes|no> Build step flag, indicates whether the "build" step is included or excluded (for development process only)
 # @set BLACKBOX_FLAG__STEP_EVALUATE type=enum<yes|no> Evaluate step flag, indicates whether the "evaluate" step is included or excluded (for development process only)
 # @set BLACKBOX_PROVISION_WITH_OPTS type=function,default=auto Provision hook definition, a function that implements an additional set of instructions that must be executed during the "provision" step
+# @set BLACKBOX_HEAP_WITH_OPTS type=function,default=auto Heap hook definition, a function that implements an additional set of heap instructions that might be executed during the "provision" step step
+# @set BLACKBOX_SNAPSHOT_WITH_OPTS type=function,default=auto Snapshot hook definition, a function that implements an additional set of snapshot instructions that might be executed during the "provision" step step
 # @set BLACKBOX_BUILD_WITH_OPTS type=function,default=auto Build hook definition, a function that implements an additional set of instructions that must be executed during the "build" step
 #
 # @set BLACKBOX_DIR readonly,type=string,default=auto Path to the Blackbox installation directory (sets automatically, do not override)
@@ -25,6 +27,7 @@
 # @set BLACKBOX_VERSION readonly,type=string,default=auto [DEPRECATED] Version of the Blackbox to use (sets automatically, do not override)
 # @set BLACKBOX_HEAP_DIR readonly,type=path,default=auto Path to the question "heap" directory, a place where question assets might be generated (sets automatically, do not override)
 # @set BLACKBOX_STORAGE_DIR readonly,type=path,default=auto Path to the question "artifacts" directory, a place where question artifacts will be generated (sets automatically, do not override)
+# @set BLACKBOX_SNAPSHOT_DIR readonly,type=path,default=auto Path to the question "snapshot" directory, a place where question snapshot will be generated (sets automatically, do not override)
 # @set BLACKBOX_BUILD_LOG readonly,type=path,default=auto Path to the build log (sets automatically, do not override)
 # @set BLACKBOX_BUILD_STREAM_DISPLAY_LINES readonly,type=integer,default=auto Number of output lines before trim and ellipsis
 #
@@ -62,10 +65,15 @@ blackbox() {
   # shellcheck disable=SC2155
   export BLACKBOX_PROVISION_WITH_OPTS=$(sed "s/\({\);/\1/g; s/\(;\)\{2\}/\1/g" <(awk 'ORS="; "' <(sed '1,2d; $d; s/[[:space:]]$//g; s/^[[:space:]]\+//g' <(declare -f BLACKBOX_PROVISION_WITH_OPTS))))
   # shellcheck disable=SC2155
+  export BLACKBOX_SNAPSHOT_WITH_OPTS=$(sed "s/\({\);/\1/g; s/\(;\)\{2\}/\1/g" <(awk 'ORS="; "' <(sed '1,2d; $d; s/[[:space:]]$//g; s/^[[:space:]]\+//g' <(declare -f BLACKBOX_SNAPSHOT_WITH_OPTS))))
+  # shellcheck disable=SC2155
+  export BLACKBOX_HEAP_WITH_OPTS=$(sed "s/\({\);/\1/g; s/\(;\)\{2\}/\1/g" <(awk 'ORS="; "' <(sed '1,2d; $d; s/[[:space:]]$//g; s/^[[:space:]]\+//g' <(declare -f BLACKBOX_HEAP_WITH_OPTS))))
+  # shellcheck disable=SC2155
   export BLACKBOX_BUILD_WITH_OPTS=$(sed "s/\({\);/\1/g; s/\(;\)\{2\}/\1/g" <(awk 'ORS="; "' <(sed '1,2d; $d; s/[[:space:]]$//g; s/^[[:space:]]\+//g' <(declare -f BLACKBOX_BUILD_WITH_OPTS))))
 
-  export BLACKBOX_HEAP_DIR="/tmp/${3}"
+  export BLACKBOX_HEAP_DIR="/tmp/data"
   export BLACKBOX_STORAGE_DIR="/var/save/${3}"
+  export BLACKBOX_SNAPSHOT_DIR="${BLACKBOX_STORAGE_DIR}/.snapshot"
   export BLACKBOX_BUILD_LOG="${BLACKBOX_STORAGE_DIR}/build.log"
   export BLACKBOX_BUILD_STREAM_DISPLAY_LINES=255
 
@@ -220,8 +228,8 @@ blackbox() {
       declare header=$(</dev/stdin)
 
       typeset entrypoint=$1
-      typeset args=("$2")
-      typeset opts=("$3")
+      typeset -a args=("$2")
+      typeset -a opts=("$3")
 
       if [ -n "${args[*]}" ]; then
         args=("$(sed ':a;N;$!ba;s/\n/\t/g; s/[[:space:]]\+/ /g' <<<"${args[*]/#/ < }")")
@@ -271,7 +279,7 @@ blackbox() {
 
     if [ ! -e "$BLACKBOX_DIR" ]; then
       wget -S --output-document="/tmp/blackbox.zip" "https://codeload.github.com/ProblemSetters/devops-blackbox/zip/refs/heads/${BLACKBOX_VERSION}" && {
-        unzip /tmp/blackbox.zip -x "devops-blackbox-2404/.github/*" "devops-blackbox-2404/docs/*" "devops-blackbox-2404/tests/*" "devops-blackbox-2404/.gitignore" "devops-blackbox-2404/Makefile.*" "devops-blackbox-2404/README.md" "devops-blackbox-2404/Vagrantfile" -d /tmp && {
+        unzip /tmp/blackbox.zip -x "devops-blackbox-2404/.github/*" "devops-blackbox-2404/docs/*" "devops-blackbox-2404/tests/*" "devops-blackbox-2404/.editorconfig" "devops-blackbox-2404/.gitignore" "devops-blackbox-2404/Makefile.*" "devops-blackbox-2404/README.md" "devops-blackbox-2404/Vagrantfile" -d /tmp && {
           mv "/tmp/devops-blackbox-${BLACKBOX_VERSION}" "$BLACKBOX_DIR"
           rm -rf /tmp/*blackbox*
         }
@@ -288,7 +296,7 @@ blackbox() {
     fi
 
     blackbox.framework.inventory.install.directory "$BLACKBOX_USER_QUESTION_DIR" && {
-      pushd "$BLACKBOX_USER_QUESTION_DIR" && {
+      pushd "$BLACKBOX_USER_QUESTION_DIR" &>/dev/null && {
         blackbox.framework.module.load "$module_name" "${module_args[@]}"
       }
     }