diff --git a/2022/RESULTS.txt b/2022/RESULTS.txt
index 01c9bc7..595e0a1 100644
--- a/2022/RESULTS.txt
+++ b/2022/RESULTS.txt
@@ -183,7 +183,15 @@ aoc.bash: res=5619
 	time: 0:00.69 real, 0.69 user, 0.00 sys
 	context-switch:	38+1, page-faults: 0+430
 
+aoc-c: res=5619
+	time: 0:00.00 real, 0.00 user, 0.00 sys
+	context-switch:	0+1, page-faults: 0+158
+
 +++++++++++++++++ part 2
 aoc.bash: res=2376
 	time: 0:03.25 real, 3.24 user, 0.00 sys
 	context-switch:	46+1, page-faults: 0+340
+
+aoc-c: res=2376
+	time: 0:00.00 real, 0.00 user, 0.00 sys
+	context-switch:	0+1, page-faults: 0+131
diff --git a/2022/day10/Makefile b/2022/day10/Makefile
new file mode 100644
index 0000000..e0add74
--- /dev/null
+++ b/2022/day10/Makefile
@@ -0,0 +1,111 @@
+# AOC daily Makefile - GNU make only.
+#
+# Copyright (C) 2021-2022 Bruno Raoult ("br")
+# Licensed under the GNU General Public License v3.0 or later.
+# Some rights reserved. See COPYING.
+#
+# You should have received a copy of the GNU General Public License along with this
+# program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+#
+# SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+#
+
+INPUT   := input/input.txt
+SHELL   := /bin/bash
+
+CC      := gcc
+BEAR    := bear
+CCLSFILE:= compile_commands.json
+
+LIB     := aoc_$(shell uname -m)
+INCDIR  := ../include
+LIBDIR  := ../lib
+LDFLAGS := -L$(LIBDIR)
+#LDLIB   := -l$(LIB) -lm
+LDLIB   := -l$(LIB)
+
+export LD_LIBRARY_PATH = $(LIBDIR)
+
+CFLAGS  += -std=gnu11
+CFLAGS  += -O2
+CFLAGS  += -g
+# for gprof
+# CFLAGS += -pg
+CFLAGS  += -Wall
+CFLAGS  += -Wextra
+CFLAGS  += -march=native
+# Next one may be useful for valgrind (some invalid instructions)
+# CFLAGS += -mno-tbm
+CFLAGS  += -Wmissing-declarations
+CFLAGS  += -Wno-unused-result
+
+CFLAGS  += -DDEBUG_DEBUG 	# activate general debug (debug.c)
+CFLAGS  += -DDEBUG_POOL		# memory pools management
+
+VALGRIND := valgrind
+VALGRINDFLAGS := --leak-check=full --show-leak-kinds=all --track-origins=yes \
+	--sigill-diagnostics=yes --quiet --show-error-list=yes
+
+
+TIME    := \time -f "\ttime: %E real, %U user, %S sys\n\tcontext-switch:\t%c+%w, page-faults: %F+%R\n"
+export PATH := .:$(PATH)
+
+.PHONY: clean all compile assembly memcheck memcheck1 memcheck2 part1 part2 ccls bear org
+
+all: README.org ccls part1 part2
+
+memcheck: memcheck1 memcheck2
+
+memcheck1: aoc-c
+	@$(VALGRIND) $(VALGRINDFLAGS) aoc-c -p 1 < $(INPUT)
+
+memcheck2: aoc-c
+	@$(VALGRIND) $(VALGRINDFLAGS) aoc-c -p 2 < $(INPUT)
+	@#@valgrind -s --track-origins=yes aoc-c -p 2 < $(INPUT)
+
+compile: aoc-c
+
+cpp: aoc-c.i
+
+assembly: aoc-c.s
+
+part1: aoc-c
+	@$(TIME) aoc.bash -p 1 < $(INPUT) 2>&1
+	@$(TIME) aoc-c -p 1 < $(INPUT)
+
+part2: aoc-c
+	@$(TIME) aoc.bash -p 2 < $(INPUT) 2>&1
+	@$(TIME) aoc-c -p 2 < $(INPUT)
+
+ccls: $(CCLSFILE)
+
+clean:
+	@rm -f aoc-c core* vgcore* gmon.out aoc-c.s aoc-c.i README.html compile_commands.json
+
+aoc-c: aoc-c.c common.c
+	@echo compiling $<
+	$(CC) $(CFLAGS) $(LDFLAGS) -I $(INCDIR) $^ $(LDLIB) -o $@
+
+# generate pre-processed file (.i) and assembler (.s)
+%.i: %.c
+	@echo generating $@
+	@$(CC) -E $(CFLAGS) -I $(INCDIR) $< -o $@
+
+%.s: %.c
+	@echo generating $@
+	@$(CC) -S -fverbose-asm $(CFLAGS) -I $(INCDIR) $< -o $@
+
+# generate README.org from README.html (must cleanup !)
+org: README.org
+
+%.org: %.html
+	@echo generating $@. Cleanup before commit !
+	@pandoc $< -o $@
+
+# generate compile_commands.json
+$(CCLSFILE): aoc-c.c Makefile
+	$(BEAR) -- make clean compile
+
+bear: clean
+	@touch .ccls-root
+	@$(BEAR) -- make compile
diff --git a/2022/day10/README.org b/2022/day10/README.org
new file mode 100644
index 0000000..093648a
--- /dev/null
+++ b/2022/day10/README.org
@@ -0,0 +1,231 @@
+** --- Day 10: Cathode-Ray Tube ---
+You avoid the ropes, plunge into the river, and swim to shore.
+
+The Elves yell something about meeting back up with them upriver, but
+the river is too loud to tell exactly what they're saying. They finish
+crossing the bridge and disappear from view.
+
+Situations like this must be why the Elves prioritized getting the
+communication system on your handheld device working. You pull it out of
+your pack, but the amount of water slowly draining from a big crack in
+its screen tells you it probably won't be of much immediate use.
+
+/Unless/, that is, you can design a replacement for the device's video
+system! It seems to be some kind of
+[[https://en.wikipedia.org/wiki/Cathode-ray_tube][cathode-ray tube]]
+screen and simple CPU that are both driven by a precise /clock circuit/.
+The clock circuit ticks at a constant rate; each tick is called a
+/cycle/.
+
+Start by figuring out the signal being sent by the CPU. The CPU has a
+single register, =X=, which starts with the value =1=. It supports only
+two instructions:
+
+- =addx V= takes /two cycles/ to complete. /After/ two cycles, the =X=
+  register is increased by the value =V=. (=V= can be negative.)
+- =noop= takes /one cycle/ to complete. It has no other effect.
+
+The CPU uses these instructions in a program (your puzzle input) to,
+somehow, tell the screen what to draw.
+
+Consider the following small program:
+
+#+begin_example
+noop
+addx 3
+addx -5
+#+end_example
+
+Execution of this program proceeds as follows:
+
+- At the start of the first cycle, the =noop= instruction begins
+  execution. During the first cycle, =X= is =1=. After the first cycle,
+  the =noop= instruction finishes execution, doing nothing.
+- At the start of the second cycle, the =addx 3= instruction begins
+  execution. During the second cycle, =X= is still =1=.
+- During the third cycle, =X= is still =1=. After the third cycle, the
+  =addx 3= instruction finishes execution, setting =X= to =4=.
+- At the start of the fourth cycle, the =addx -5= instruction begins
+  execution. During the fourth cycle, =X= is still =4=.
+- During the fifth cycle, =X= is still =4=. After the fifth cycle, the
+  =addx -5= instruction finishes execution, setting =X= to =-1=.
+
+Maybe you can learn something by looking at the value of the =X=
+register throughout execution. For now, consider the /signal strength/
+(the cycle number multiplied by the value of the =X= register) /during/
+the 20th cycle and every 40 cycles after that (that is, during the 20th,
+60th, 100th, 140th, 180th, and 220th cycles).
+
+For example, consider this larger program:
+
+#+begin_example
+addx 15
+addx -11
+addx 6
+addx -3
+addx 5
+addx -1
+addx -8
+addx 13
+addx 4
+noop
+addx -1
+addx 5
+addx -1
+addx 5
+addx -1
+addx 5
+addx -1
+addx 5
+addx -1
+addx -35
+addx 1
+addx 24
+addx -19
+addx 1
+addx 16
+addx -11
+noop
+noop
+addx 21
+addx -15
+noop
+noop
+addx -3
+addx 9
+addx 1
+addx -3
+addx 8
+addx 1
+addx 5
+noop
+noop
+noop
+noop
+noop
+addx -36
+noop
+addx 1
+addx 7
+noop
+noop
+noop
+addx 2
+addx 6
+noop
+noop
+noop
+noop
+noop
+addx 1
+noop
+noop
+addx 7
+addx 1
+noop
+addx -13
+addx 13
+addx 7
+noop
+addx 1
+addx -33
+noop
+noop
+noop
+addx 2
+noop
+noop
+noop
+addx 8
+noop
+addx -1
+addx 2
+addx 1
+noop
+addx 17
+addx -9
+addx 1
+addx 1
+addx -3
+addx 11
+noop
+noop
+addx 1
+noop
+addx 1
+noop
+noop
+addx -13
+addx -19
+addx 1
+addx 3
+addx 26
+addx -30
+addx 12
+addx -1
+addx 3
+addx 1
+noop
+noop
+noop
+addx -9
+addx 18
+addx 1
+addx 2
+noop
+noop
+addx 9
+noop
+noop
+noop
+addx -1
+addx 2
+addx -37
+addx 1
+addx 3
+noop
+addx 15
+addx -21
+addx 22
+addx -6
+addx 1
+noop
+addx 2
+addx 1
+noop
+addx -10
+noop
+noop
+addx 20
+addx 1
+addx 2
+addx 2
+addx -6
+addx -11
+noop
+noop
+noop
+#+end_example
+
+The interesting signal strengths can be determined as follows:
+
+- During the 20th cycle, register =X= has the value =21=, so the signal
+  strength is 20 * 21 = /420/. (The 20th cycle occurs in the middle of
+  the second =addx -1=, so the value of register =X= is the starting
+  value, =1=, plus all of the other =addx= values up to that point: 1 +
+  15 - 11 + 6 - 3 + 5 - 1 - 8 + 13 + 4 = 21.)
+- During the 60th cycle, register =X= has the value =19=, so the signal
+  strength is 60 * 19 = =1140=.
+- During the 100th cycle, register =X= has the value =18=, so the signal
+  strength is 100 * 18 = =1800=.
+- During the 140th cycle, register =X= has the value =21=, so the signal
+  strength is 140 * 21 = =2940=.
+- During the 180th cycle, register =X= has the value =16=, so the signal
+  strength is 180 * 16 = =2880=.
+- During the 220th cycle, register =X= has the value =18=, so the signal
+  strength is 220 * 18 = =3960=.
+
+The sum of these signal strengths is =13140=.
+
+Find the signal strength during the 20th, 60th, 100th, 140th, 180th, and
+220th cycles. /What is the sum of these six signal strengths?/
diff --git a/2022/day10/aoc.h b/2022/day10/aoc.h
new file mode 100644
index 0000000..2ef8361
--- /dev/null
+++ b/2022/day10/aoc.h
@@ -0,0 +1,17 @@
+/* aoc.c: Advent of Code 2022
+ *
+ * Copyright (C) 2022 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ */
+#ifndef _AOC_H_
+#define _AOC_H_
+
+extern int parseargs(int ac, char**av);
+
+#endif  /* _AOC_H_ */
diff --git a/2022/day10/common.bash b/2022/day10/common.bash
new file mode 100755
index 0000000..5af1e54
--- /dev/null
+++ b/2022/day10/common.bash
@@ -0,0 +1,68 @@
+#!/usr/bin/env bash
+#
+# common.bash: Advent of Code 2022, common bash functions
+#
+# Copyright (C) 2022 Bruno Raoult ("br")
+# Licensed under the GNU General Public License v3.0 or later.
+# Some rights reserved. See COPYING.
+#
+# You should have received a copy of the GNU General Public License along with this
+# program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+#
+# SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+
+# shellcheck disable=2034
+export cmdname=${0##*/}
+export debug=0
+export res
+export LANG=C
+
+shopt -s extglob
+set -o noglob
+
+usage() {
+    printf "usage: %s [-d DEBUG] [-p PART]\n" "$cmdname"
+    exit 1
+}
+
+checkargs() {
+    local part=1
+    while getopts p:d: todo; do
+        case "$todo" in
+            d)
+                if [[ "$OPTARG" =~ ^[[:digit:]+]$ ]]; then
+                    debug="$OPTARG"
+                else
+                    printf "%s: illegal [%s] debug level.\n" "$CMD" "$OPTARG"
+                    exit 1
+                fi
+                ;;
+            p)
+                if [[ "$OPTARG" =~ ^[12]$ ]]; then
+                    part="$OPTARG"
+                else
+                    printf "%s: illegal [%s] part.\n" "$CMD" "$OPTARG"
+                    exit 1
+                fi
+                ;;
+            *)
+                usage
+                ;;
+        esac
+    done
+    # Now check remaining argument (backup directory)
+    shift $((OPTIND - 1))
+
+    (( $# > 1 )) && usage
+    return "$part"
+}
+
+main() {
+    local -i part
+
+    checkargs "$@"
+    part=$?
+    parse "$part"
+    solve "$part"
+    printf "%s: res=%s\n" "$cmdname" "$res"
+}
diff --git a/2022/day10/common.c b/2022/day10/common.c
new file mode 100644
index 0000000..a3827b6
--- /dev/null
+++ b/2022/day10/common.c
@@ -0,0 +1,49 @@
+/* common.c: Advent of Code 2022, common functions
+ *
+ * Copyright (C) 2022 Bruno Raoult ("br")
+ * Licensed under the GNU General Public License v3.0 or later.
+ * Some rights reserved. See COPYING.
+ *
+ * You should have received a copy of the GNU General Public License along with this
+ * program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include "aoc.h"
+#include "debug.h"
+
+static int usage(char *prg)
+{
+    fprintf(stderr, "Usage: %s [-d debug_level] [-p part] [-i input]\n", prg);
+    return 1;
+}
+
+int parseargs(int ac, char **av)
+{
+    int opt, part = 1;
+
+    while ((opt = getopt(ac, av, "d:p:")) != -1) {
+        switch (opt) {
+            case 'd':
+                debug_level_set(atoi(optarg));
+                break;
+            case 'p':                             /* 1 or 2 */
+                part = atoi(optarg);
+                if (part < 1 || part > 2)
+                    return usage(*av);
+                break;
+            case 'i':
+
+            default:
+                return usage(*av);
+        }
+    }
+    if (optind < ac)
+        return usage(*av);
+    return part;
+}
diff --git a/2022/day10/input/example.txt b/2022/day10/input/example.txt
new file mode 100644
index 0000000..37ee8ee
--- /dev/null
+++ b/2022/day10/input/example.txt
@@ -0,0 +1,146 @@
+addx 15
+addx -11
+addx 6
+addx -3
+addx 5
+addx -1
+addx -8
+addx 13
+addx 4
+noop
+addx -1
+addx 5
+addx -1
+addx 5
+addx -1
+addx 5
+addx -1
+addx 5
+addx -1
+addx -35
+addx 1
+addx 24
+addx -19
+addx 1
+addx 16
+addx -11
+noop
+noop
+addx 21
+addx -15
+noop
+noop
+addx -3
+addx 9
+addx 1
+addx -3
+addx 8
+addx 1
+addx 5
+noop
+noop
+noop
+noop
+noop
+addx -36
+noop
+addx 1
+addx 7
+noop
+noop
+noop
+addx 2
+addx 6
+noop
+noop
+noop
+noop
+noop
+addx 1
+noop
+noop
+addx 7
+addx 1
+noop
+addx -13
+addx 13
+addx 7
+noop
+addx 1
+addx -33
+noop
+noop
+noop
+addx 2
+noop
+noop
+noop
+addx 8
+noop
+addx -1
+addx 2
+addx 1
+noop
+addx 17
+addx -9
+addx 1
+addx 1
+addx -3
+addx 11
+noop
+noop
+addx 1
+noop
+addx 1
+noop
+noop
+addx -13
+addx -19
+addx 1
+addx 3
+addx 26
+addx -30
+addx 12
+addx -1
+addx 3
+addx 1
+noop
+noop
+noop
+addx -9
+addx 18
+addx 1
+addx 2
+noop
+noop
+addx 9
+noop
+noop
+noop
+addx -1
+addx 2
+addx -37
+addx 1
+addx 3
+noop
+addx 15
+addx -21
+addx 22
+addx -6
+addx 1
+noop
+addx 2
+addx 1
+noop
+addx -10
+noop
+noop
+addx 20
+addx 1
+addx 2
+addx 2
+addx -6
+addx -11
+noop
+noop
+noop
diff --git a/2022/day10/input/example2.txt b/2022/day10/input/example2.txt
new file mode 100644
index 0000000..f428b7b
--- /dev/null
+++ b/2022/day10/input/example2.txt
@@ -0,0 +1,3 @@
+noop
+addx 3
+addx -5
diff --git a/2022/day10/input/input.txt b/2022/day10/input/input.txt
new file mode 100644
index 0000000..734f57f
--- /dev/null
+++ b/2022/day10/input/input.txt
@@ -0,0 +1,137 @@
+noop
+noop
+addx 5
+addx 3
+addx -2
+noop
+addx 5
+addx 4
+noop
+addx 3
+noop
+addx 2
+addx -17
+addx 18
+addx 3
+addx 1
+noop
+addx 5
+noop
+addx 1
+addx 2
+addx 5
+addx -40
+noop
+addx 5
+addx 2
+addx 3
+noop
+addx 2
+addx 3
+addx -2
+addx 2
+addx 2
+noop
+addx 3
+addx 5
+addx 2
+addx 3
+addx -2
+addx 2
+addx -24
+addx 31
+addx 2
+addx -33
+addx -6
+addx 5
+addx 2
+addx 3
+noop
+addx 2
+addx 3
+noop
+addx 2
+addx -1
+addx 6
+noop
+noop
+addx 1
+addx 4
+noop
+noop
+addx -15
+addx 20
+noop
+addx -23
+addx 27
+noop
+addx -35
+addx 1
+noop
+noop
+addx 5
+addx 11
+addx -10
+addx 4
+addx 1
+noop
+addx 2
+addx 2
+noop
+addx 3
+noop
+addx 3
+addx 2
+noop
+addx 3
+addx 2
+addx 11
+addx -4
+addx 2
+addx -38
+addx -1
+addx 2
+noop
+addx 3
+addx 5
+addx 2
+addx -7
+addx 8
+addx 2
+addx 2
+noop
+addx 3
+addx 5
+addx 2
+addx -25
+addx 26
+addx 2
+addx 8
+addx -1
+addx 2
+addx -2
+addx -37
+addx 5
+addx 3
+addx -1
+addx 5
+noop
+addx 22
+addx -21
+addx 2
+addx 5
+addx 2
+addx 13
+addx -12
+addx 4
+noop
+noop
+addx 5
+addx 1
+noop
+noop
+addx 2
+noop
+addx 3
+noop
+noop