diff --git a/2019/day03/EXAMPLE.txt b/2019/day03/EXAMPLE.txt
new file mode 100644
index 0000000..620a05e
--- /dev/null
+++ b/2019/day03/EXAMPLE.txt
@@ -0,0 +1,2 @@
+R75,D30,R83,U83,L12,D49,R71,U7,L72
+U62,R66,U55,R34,D71,R55,D58,R83
diff --git a/2019/day03/EXAMPLE2.txt b/2019/day03/EXAMPLE2.txt
new file mode 100644
index 0000000..4f3a2a4
--- /dev/null
+++ b/2019/day03/EXAMPLE2.txt
@@ -0,0 +1,2 @@
+R98,U47,R26,D63,R33,U87,L62,D20,R33,U53,R51
+U98,R91,D20,R16,D67,R40,U7,R15,U6,R7
diff --git a/2019/day03/INPUT.txt b/2019/day03/INPUT.txt
new file mode 100644
index 0000000..5c5cc7a
--- /dev/null
+++ b/2019/day03/INPUT.txt
@@ -0,0 +1,2 @@
+R1000,D722,L887,D371,R430,D952,R168,D541,L972,D594,R377,U890,R544,U505,L629,U839,L680,D863,L315,D10,L482,U874,L291,U100,R770,D717,L749,U776,L869,D155,R250,U672,L195,D991,L556,D925,R358,U296,R647,D652,L790,D780,L865,U405,L400,D160,L460,U50,R515,D666,R306,U746,R754,U854,L332,U254,R673,U795,R560,U69,L507,U332,L328,U547,L717,U291,R626,U868,L583,D256,R371,U462,R793,U559,L571,U270,R738,U425,L231,U549,L465,U21,L647,U43,R847,U104,L699,U378,L549,D975,R13,D306,R532,D730,L566,U846,L903,D224,R448,D424,L727,D199,L626,D872,L541,D786,L304,U462,R347,U379,R29,D556,L775,D768,L284,D480,R654,D659,R818,D57,L77,U140,R619,D148,R686,D461,L910,U244,R115,D769,R968,U802,L737,U868,R399,D150,L791,U579,L856,D11,R115,U522,L443,D575,L133,U750,R437,U718,L79,D119,L97,U471,R817,U438,R157,U105,L219,U777,L965,U687,L906,D744,L983,D350,R664,D917,R431,D721,L153,U757,L665,U526,L49,U166,L59,D293,R962,D764,R538,U519,L24,U91,R11,U574,L647,U891,R44,D897,L715,U498,L624,D573,R287,U762,L613,D79,R122,U148,L849,D385,R792,D20,L512,D431,R818,U428,L10,D800,R773,D936,L594,D38,R824,D216,L220,U358,L463,U550,R968,D346,L658,U113,R813,U411,L730,D84,R479,U877,L730,D961,L839,D792,R424,U321,L105,D862,L815,D243,L521,D913,L1,D513,L269,U495,L27,U16,R904,D926,R640,U948,R346,D240,L273,U131,L296,U556,R347,D640,L261,D43,R136,U824,R126,U583,R736,U530,L734,U717,L256,U362,L86,U48,R851,U519,L610,D134,L554,D766,L179,U637,R71,D895,L21,D908,R486,D863,R31,U85,R420,D718,R466,D861,R655,D304,L701,D403,L860,D208,L595,U64,R999
+L992,D463,R10,D791,R312,D146,R865,D244,L364,D189,R35,U328,R857,D683,L660,D707,L908,D277,R356,U369,R197,D35,R625,D862,L769,U705,L728,U999,R938,U233,L595,U266,L697,U966,L536,D543,L669,D829,R910,U693,R753,D389,L647,U603,L660,D787,L138,D119,L131,D266,R268,D917,R776,U290,R920,U904,L46,D139,L341,D19,R982,U790,L981,U791,L147,U30,L246,U677,R343,D492,R398,D234,R76,D423,L709,D392,R741,U408,R878,U29,R446,U36,R806,U78,L76,D813,R584,U682,L187,U666,L340,D301,L694,U15,R800,U276,L755,U558,R366,D309,R571,U976,L286,D833,R318,U365,L864,U408,L352,D61,R284,D272,R240,D845,L206,U721,R367,D541,R628,U581,L750,D680,R695,D30,R849,U743,L214,U605,R533,U493,R803,D783,R168,U877,L61,D726,L794,D116,R717,U44,R964,U674,L291,D372,L381,D523,L644,U438,R983,D390,R520,D471,R556,D693,L919,D863,R84,D629,L264,D429,R82,U64,R835,D801,R93,U770,R441,D152,L718,D788,L797,U699,L82,U206,L40,U952,R902,U570,L759,D655,L131,D901,L470,D804,L407,U458,L922,D21,L171,U841,L237,D301,R192,D293,R984,U243,R846,U139,L413,U162,R925,D235,L115,U443,L884,D910,R335,U274,L338,U160,R125,D775,R824,D821,R531,D761,L189,U822,L602,D732,R473,U149,L128,U30,R77,D957,R811,D154,L988,D237,R425,D855,R482,D571,R134,D731,L905,U869,R916,D689,L17,U24,R353,D996,R832,U855,L76,U659,R581,D483,R821,D145,R199,D344,R487,D436,L92,U491,R365,D909,L17,D148,R307,U57,R666,U660,R195,D767,R612,D902,L594,D299,R670,D881,L583,D793,R58,U89,L99,D355,R394,D350,R920,U544,R887,U564,L238,U979,L565,D914,L95,U150,R292,U495,R506,U475,R813,D308,L797,D484,R9
diff --git a/2019/day03/Makefile b/2019/day03/Makefile
new file mode 100644
index 0000000..04f5b05
--- /dev/null
+++ b/2019/day03/Makefile
@@ -0,0 +1,77 @@
+# AOC daily Makefile - GNU make only.
+#
+# Copyright (C) 2021 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.txt
+SHELL   := /bin/bash
+
+CC      := gcc
+
+LIB     := aoc_$(shell uname -m)
+INCDIR  := ../include
+LIBDIR  := ../lib
+LDFLAGS := -L$(LIBDIR)
+#LDLIB   := -l$(LIB) -lm
+LDLIB   := -l$(LIB)
+
+export LD_LIBRARY_PATH = $(LIBDIR)
+
+CFLAGS  += -std=gnu99
+CFLAGS  += -O2
+CFLAGS  += -g
+# for gprof
+#CFLAGS += -pg
+CFLAGS  += -Wall
+CFLAGS  += -Wextra
+CFLAGS  += -march=native
+# Next one may be useful for valgrind (some invalid instructions)
+# CFLAGS += -mno-tbm
+CFLAGS  += -Wmissing-declarations
+CFLAGS  += -Wno-unused-result
+
+CFLAGS  += -DDEBUG_DEBUG 	# activate general debug (debug.c)
+CFLAGS  += -DDEBUG_POOL		# memory pools management
+
+TIME    := \time -f "\ttime: %E real, %U user, %S sys\n\tcontext-switch:\t%c+%w, page-faults: %F+%R\n"
+export PATH := .:$(PATH)
+
+.PHONY: clean all compile assembly memcheck memcheck1 memcheck2 ex1 ex2
+
+all: ex1 ex2
+
+memcheck: memcheck1
+
+memcheck1:
+	@valgrind -q -s --track-origins=yes aoc-c -p 1 < $(INPUT)
+
+memcheck2:
+	@valgrind -q -s --track-origins=yes aoc-c -p 2 < $(INPUT)
+
+compile: aoc-c
+
+assembly: aoc-c.s
+
+ex1: aoc-c
+	@$(TIME) aoc-c -p 1 < $(INPUT)
+
+ex2: aoc-c
+	@$(TIME) aoc-c -p 2 < $(INPUT)
+
+clean:
+	@rm -f aoc-c core* vgcore* gmon.out aoc-c.s
+
+.c:
+	@echo compiling $<
+	@$(CC) $(CFLAGS) $(LDFLAGS) -I $(INCDIR) $< $(LDLIB) -o $@
+
+.c.s:
+	@echo generating $@
+	@$(CC) -S -fverbose-asm $(CFLAGS) -I $(INCDIR) $< -o $@
diff --git a/2019/day03/README.org b/2019/day03/README.org
new file mode 100644
index 0000000..37a10ca
--- /dev/null
+++ b/2019/day03/README.org
@@ -0,0 +1,66 @@
+** --- Day 3: Crossed Wires ---
+The gravity assist was successful, and you're well on your way to the
+Venus refuelling station. During the rush back on Earth, the fuel
+management system wasn't completely installed, so that's next on the
+priority list.
+
+Opening the front panel reveals a jumble of wires. Specifically, /two
+wires/ are connected to a central port and extend outward on a grid. You
+trace the path each wire takes as it leaves the central port, one wire
+per line of text (your puzzle input).
+
+The wires twist and turn, but the two wires occasionally cross paths. To
+fix the circuit, you need to /find the intersection point closest to the
+central port/. Because the wires are on a grid, use the
+[[https://en.wikipedia.org/wiki/Taxicab_geometry][Manhattan distance]]
+for this measurement. While the wires do technically cross right at the
+central port where they both start, this point does not count, nor does
+a wire count as crossing with itself.
+
+For example, if the first wire's path is =R8,U5,L5,D3=, then starting
+from the central port (=o=), it goes right =8=, up =5=, left =5=, and
+finally down =3=:
+
+#+BEGIN_EXAMPLE
+  ...........
+  ...........
+  ...........
+  ....+----+.
+  ....|....|.
+  ....|....|.
+  ....|....|.
+  .........|.
+  .o-------+.
+  ...........
+#+END_EXAMPLE
+
+Then, if the second wire's path is =U7,R6,D4,L4=, it goes up =7=, right
+=6=, down =4=, and left =4=:
+
+#+BEGIN_EXAMPLE
+  ...........
+  .+-----+...
+  .|.....|...
+  .|..+--X-+.
+  .|..|..|.|.
+  .|.-X--+.|.
+  .|..|....|.
+  .|.......|.
+  .o-------+.
+  ...........
+#+END_EXAMPLE
+
+These wires cross at two locations (marked =X=), but the lower-left one
+is closer to the central port: its distance is =3 + 3 = 6=.
+
+Here are a few more examples:
+
+- =R75,D30,R83,U83,L12,D49,R71,U7,L72=
+  =U62,R66,U55,R34,D71,R55,D58,R83= =distance =159=
+- =R98,U47,R26,D63,R33,U87,L62,D20,R33,U53,R51=
+  =U98,R91,D20,R16,D67,R40,U7,R15,U6,R7=   =distance =135=
+
+/What is the Manhattan distance/ from the central port to the closest
+intersection?
+
+To begin, [[file:3/input][get your puzzle input]].