diff --git a/README.md b/README.md
index 8b13789..604b8ce 100644
--- a/README.md
+++ b/README.md
@@ -1 +1,25 @@
+# Advent of code
 
+My participation to advent of code 2024.
+
+Did it in zig, trying to be as memory efficient and fast as possible.
+
+## Benchmark
+
+Can be run with `zig run -O ReleaseFast benchmark.zig`
+
+| Day | Part | Mean (μs)         | Min (μs) | Max (μs) |
+|-----|------|-------------------|----------|----------|
+| 1   | 1    |      +29 ± 3.00   |      +28 |      +78 |
+| 1   | 2    |      +24 ± 2.65   |      +24 |      +56 |
+|-----|------|-------------------|----------|----------|
+| 2   | 1    |      +43 ± 8.37   |      +37 |     +241 |
+| 2   | 2    |     +328 ± 33.84  |     +298 |     +728 |
+|-----|------|-------------------|----------|----------|
+| 3   | 1    |      +24 ± 6.24   |      +20 |     +170 |
+| 3   | 2    |      +23 ± 1.73   |      +20 |      +58 |
+|-----|------|-------------------|----------|----------|
+| 4   | 2    |     +229 ± 26.15  |     +214 |     +417 |
+| 4   | 2    |     +232 ± 26.13  |     +213 |     +337 |
+|-----|------|-------------------|----------|----------|
+| Total      |     +932 ± 108.11 |     +854 |    +2085 |
diff --git a/benchmark.zig b/benchmark.zig
new file mode 100644
index 0000000..5fd61a2
--- /dev/null
+++ b/benchmark.zig
@@ -0,0 +1,98 @@
+const std = @import("std");
+const print = std.debug.print;
+
+const d11 = @import("day1/part1.zig");
+const d12 = @import("day1/part2.zig");
+const d21 = @import("day2/part1.zig");
+const d22 = @import("day2/part2.zig");
+const d31 = @import("day3/part1.zig");
+const d32 = @import("day3/part2.zig");
+const d41 = @import("day4/part1.zig");
+const d42 = @import("day4/part2.zig");
+
+const NUMBER_OF_RUN = 1000;
+
+var total_mean: i64 = 0;
+var total_min: i64 = 0;
+var total_max: i64 = 0;
+var total_std_dev: f64 = 0;
+
+pub fn main() !void {
+    separator();
+    print("| Day | Part | Mean (μs)         | Min (μs) | Max (μs) |\n", .{});
+    separator();
+    try benchmark(d11.main, 1, 1);
+    try benchmark(d12.main, 1, 2);
+    separator();
+    try benchmark(d21.main, 2, 1);
+    try benchmark(d22.main, 2, 2);
+    separator();
+    try benchmark(d31.main, 3, 1);
+    try benchmark(d32.main, 3, 2);
+    separator();
+    try benchmark(d42.main, 4, 2);
+    try benchmark(d42.main, 4, 2);
+    separator();
+    print("| Total      | {d: >8} ± {d: <6.2} | {d:>8} | {d:>8} |\n", .{ total_mean, total_std_dev, total_min, total_max });
+    separator();
+}
+
+pub fn benchmark(func: anytype, day: u8, part: u8) !void {
+    var time_buff: [NUMBER_OF_RUN]i64 = undefined;
+
+    for (0..NUMBER_OF_RUN) |i| {
+        const time_start = std.time.microTimestamp();
+        try func();
+        time_buff[i] = std.time.microTimestamp() - time_start;
+    }
+
+    // Adjusted tabs for better alignment
+    print("| {d:<3} | {d:<4} | {d:>8} ± {d:<6.2} | {d:>8} | {d:>8} |\n", .{ day, part, mean(time_buff), std_dev(time_buff), min(time_buff), max(time_buff) });
+    total_mean += mean(time_buff);
+    total_min += min(time_buff);
+    total_max += max(time_buff);
+    total_std_dev += std_dev(time_buff);
+}
+
+pub fn separator() void {
+    print("|-----|------|-------------------|----------|----------|\n", .{});
+}
+
+fn min(array: [NUMBER_OF_RUN]i64) i64 {
+    var current_min: i64 = 999999999999;
+    for (array) |value| {
+        if (value < current_min) current_min = value;
+    }
+    return current_min;
+}
+
+fn max(array: [NUMBER_OF_RUN]i64) i64 {
+    var current_max: i64 = 0;
+    for (array) |value| {
+        if (value > current_max) current_max = value;
+    }
+    return current_max;
+}
+
+fn mean(array: [NUMBER_OF_RUN]i64) i64 {
+    var total: i64 = 0;
+    for (array) |value| {
+        total += value;
+    }
+    return @divFloor(total, NUMBER_OF_RUN);
+}
+
+fn variance(array: [NUMBER_OF_RUN]i64) i64 {
+    const m = mean(array);
+    var square_diff: i64 = 0;
+    for (array) |value| {
+        square_diff += (value - m) * (value - m);
+    }
+    return @divFloor(square_diff, NUMBER_OF_RUN);
+}
+
+fn std_dev(array: [NUMBER_OF_RUN]i64) f64 {
+    const vari = @as(f64, @floatFromInt(variance(array)));
+
+    return @sqrt(vari);
+}
diff --git a/day1/main.zig b/day1/part1.zig
similarity index 76%
rename from day1/main.zig
rename to day1/part1.zig
index 75e1592..5cf2cd6 100644
--- a/day1/main.zig
+++ b/day1/part1.zig
@@ -4,7 +4,6 @@ const print = std.debug.print;
 var file_buf: [1024 * 1024]u8 = undefined; // The file do 20kB, I give it 1MB
 
 pub fn main() !void {
-    const time_start = std.time.microTimestamp();
     var left: [1000]i32 = undefined;
     var right: [1000]i32 = undefined;
 
@@ -24,16 +23,7 @@ pub fn main() !void {
     std.mem.sort(i32, &left, {}, comptime std.sort.asc(i32));
     std.mem.sort(i32, &right, {}, comptime std.sort.asc(i32));
 
-    const time_parsing = std.time.microTimestamp();
-    print("Parsing time: {d}μs\n", .{time_parsing - time_start});
-
-    const total_distance = distance(left, right);
-    const total_similarity = try similarity(left, right);
-
-    const time_end = std.time.microTimestamp();
-    print("Compute time: {d}μs\n", .{time_end - time_parsing});
-    print("\tDistance: {d}\n", .{total_distance});
-    print("\tSimilarity: {d}\n", .{total_similarity});
+    try std.testing.expectEqual(1110981, distance(left, right));
 }
 
 fn distance(left: [1000]i32, right: [1000]i32) u32 {
diff --git a/day1/part2.zig b/day1/part2.zig
new file mode 100644
index 0000000..4519f1a
--- /dev/null
+++ b/day1/part2.zig
@@ -0,0 +1,56 @@
+const std = @import("std");
+const print = std.debug.print;
+
+var file_buf: [1024 * 1024]u8 = undefined; // The file do 20kB, I give it 1MB
+
+pub fn main() !void {
+    var left: [1000]i32 = undefined;
+    var right: [1000]i32 = undefined;
+
+    const file = try std.fs.cwd().openFile("day1/input", .{});
+    defer file.close();
+    const len = try file.readAll(&file_buf);
+
+    var i: u32 = 0;
+    var iter = std.mem.split(u8, file_buf[0..len], "\n");
+    while (iter.next()) |line| {
+        if (i == 1000) continue;
+        left[i] = try std.fmt.parseInt(i32, line[0..5], 10);
+        right[i] = try std.fmt.parseInt(i32, line[8..13], 10);
+        i += 1;
+    }
+
+    try std.testing.expectEqual(24869388, similarity(left, right));
+}
+
+fn distance(left: [1000]i32, right: [1000]i32) u32 {
+    var total_distance: u32 = 0;
+    for (left, right) |l, r| {
+        total_distance += @abs(r - l);
+    }
+    return total_distance;
+}
+
+fn similarity(left: [1000]i32, right: [1000]i32) !i32 {
+    // Make a map with value -> occurence
+    var buff: [1024 * 100]u8 = undefined;
+    var fbuf = std.heap.FixedBufferAllocator.init(&buff);
+    const allocator = fbuf.allocator();
+
+    var map = std.AutoHashMap(i32, u8).init(allocator);
+    defer map.deinit();
+
+    for (right) |r| {
+        if (map.get(r)) |r_count| {
+            try map.put(r, r_count + 1);
+        } else {
+            try map.put(r, 1);
+        }
+    }
+
+    var total_similarity: i32 = 0;
+    for (left) |l| {
+        if (map.get(l)) |r_count| total_similarity += l * r_count;
+    }
+    return total_similarity;
+}
diff --git a/day2/part1.zig b/day2/part1.zig
new file mode 100644
index 0000000..7caa0c7
--- /dev/null
+++ b/day2/part1.zig
@@ -0,0 +1,60 @@
+const std = @import("std");
+const print = std.debug.print;
+
+const State = enum { First, Second, Incr, Decr }; // Increase Decrease
+
+var file_buf: [1024 * 1024]u8 = undefined; // The file do 20kB, I give it 1MB
+var second_buf: [64]u8 = undefined;
+
+pub fn main() !void {
+    const file = try std.fs.cwd().openFile("day2/input", .{});
+    defer file.close();
+    const len = try file.readAll(&file_buf);
+
+    var total_safe: usize = 0;
+    var iter = std.mem.split(u8, file_buf[0..len], "\n");
+    while (iter.next()) |line| {
+        if (std.mem.eql(u8, line, "")) continue;
+
+        if (try isSafe(line)) {
+            total_safe += 1;
+            continue;
+        }
+    }
+
+    try std.testing.expectEqual(564, total_safe);
+}
+
+fn isSafe(line: []const u8) !bool {
+    var state: State = .First;
+    var previous: u8 = 0;
+    var current: u8 = 0;
+
+    var it = std.mem.split(u8, line, " ");
+    while (it.next()) |x| {
+        defer previous = current;
+        current = try std.fmt.parseInt(u8, x, 10);
+
+        if (state != .First and previous == current) return false;
+        if (state != .First and ((previous > current and (previous - current) > 3) or (previous < current and (current - previous) > 3))) return false;
+
+        state = switch (state) {
+            .First => .Second,
+            .Second => if (previous > current) .Decr else .Incr,
+            .Decr => if (previous > current) .Decr else return false,
+            .Incr => if (previous < current) .Incr else return false,
+        };
+    }
+
+    return true;
+}
+
+test "Is safe" {
+    try std.testing.expect(try isSafe("1 2 3"));
+    try std.testing.expect(try isSafe("1 2 3 4 5 6 7 8 9"));
+    try std.testing.expect(try isSafe("243 241 239"));
+    try std.testing.expect(!try isSafe("1 2 3 8"));
+    try std.testing.expect(!try isSafe("1 2 3 2 1"));
+    try std.testing.expect(!try isSafe("1 2 3 3 1"));
+    try std.testing.expect(!try isSafe("1 1 3 3 1"));
+}
diff --git a/day2/main.zig b/day2/part2.zig
similarity index 68%
rename from day2/main.zig
rename to day2/part2.zig
index 5e34a08..16c3d57 100644
--- a/day2/main.zig
+++ b/day2/part2.zig
@@ -3,57 +3,43 @@ const print = std.debug.print;
 
 const State = enum { First, Second, Incr, Decr }; // Increase Decrease
 
-var line_buf: [64]u8 = undefined;
+var file_buf: [1024 * 1024]u8 = undefined; // The file do 20kB, I give it 1MB
 var second_buf: [64]u8 = undefined;
-var previous: u8 = 0;
-var current: u8 = 0;
 
 pub fn main() !void {
-    const time_start = std.time.microTimestamp();
-
-    var fbuf = std.heap.FixedBufferAllocator.init(&line_buf);
-    const alloc = fbuf.allocator();
-    var line = std.ArrayList(u8).initCapacity(alloc, line_buf.len) catch unreachable;
-
     const file = try std.fs.cwd().openFile("day2/input", .{});
     defer file.close();
+    const len = try file.readAll(&file_buf);
 
-    var buf_reader = std.io.bufferedReader(file.reader());
-    const reader = buf_reader.reader();
-
-    const writer = line.writer();
     var total_safe: usize = 0;
-    while (reader.streamUntilDelimiter(writer, '\n', null)) {
-        // Clear the line so we can reuse it.
-        defer line.clearRetainingCapacity();
+    var iter = std.mem.split(u8, file_buf[0..len], "\n");
+    while (iter.next()) |line| {
+        if (std.mem.eql(u8, line, "")) continue;
 
-        if (try isSafe(line.items)) {
+        if (try isSafe(line)) {
             total_safe += 1;
             continue;
         }
 
         var i: u8 = 0;
-        var it = std.mem.split(u8, line.items, " ");
+        var it = std.mem.split(u8, line, " ");
         while (it.next()) |_| {
-            const new_line = try removeOneIndex(line.items, i);
+            const new_line = try removeOneIndex(line, i);
             if (try isSafe(new_line)) {
                 total_safe += 1;
                 break;
             }
             i += 1;
         }
-    } else |err| switch (err) {
-        error.EndOfStream => {},
-        else => return err, // Propagate error
     }
 
-    const time_end = std.time.microTimestamp();
-    print("Total time: {d}μs\n", .{time_end - time_start});
-    print("Total safe: {d}\n", .{total_safe});
+    try std.testing.expectEqual(604, total_safe);
 }
 
 fn isSafe(line: []const u8) !bool {
     var state: State = .First;
+    var previous: u8 = 0;
+    var current: u8 = 0;
 
     var it = std.mem.split(u8, line, " ");
     while (it.next()) |x| {
diff --git a/day3/part1.zig b/day3/part1.zig
new file mode 100644
index 0000000..50c8036
--- /dev/null
+++ b/day3/part1.zig
@@ -0,0 +1,78 @@
+const std = @import("std");
+const print = std.debug.print;
+
+const LookingFor = enum {
+    m,
+    u,
+    l,
+    l_brace,
+    X,
+    Y,
+};
+
+var file_buf: [1024 * 1024]u8 = undefined; // The file do 20kB, I give it 1MB
+
+pub fn main() !void {
+    const file = try std.fs.cwd().openFile("day3/input", .{});
+    defer file.close();
+    const len = try file.readAll(&file_buf);
+
+    try std.testing.expectEqual(190604937, try parse(file_buf[0..len]));
+}
+
+fn parse(input: []const u8) !u32 {
+    var state: LookingFor = .m;
+    var total: u32 = 0;
+    var intX_len: u8 = 0;
+    var intY_len: u8 = 0;
+    for (input, 0..) |c, i| switch (state) {
+        .m => switch (c) {
+            'm' => state = .u,
+            else => continue,
+        },
+        .u => switch (c) {
+            'u' => state = .l,
+            else => state = .m,
+        },
+        .l => switch (c) {
+            'l' => state = .l_brace,
+            else => state = .m,
+        },
+        .l_brace => switch (c) {
+            '(' => {
+                state = .X;
+                intX_len = 0;
+                intY_len = 0;
+            },
+            else => state = .m,
+        },
+        .X => switch (c) {
+            ',' => state = if (intX_len > 0) .Y else .m,
+            '0'...'9' => if (intX_len == 3) {
+                state = .m;
+            } else {
+                intX_len += 1;
+            },
+            else => state = .m,
+        },
+        .Y => switch (c) {
+            ')' => {
+                state = .m;
+                if (intY_len > 0) {
+                    const x = try std.fmt.parseInt(u32, input[i - (intX_len + intY_len + 1) .. i - intY_len - 1], 10);
+                    const y = try std.fmt.parseInt(u32, input[i - intY_len .. i], 10);
+                    total += x * y;
+                }
+            },
+            '0'...'9' => {
+                if (intY_len == 3) {
+                    state = .m;
+                    continue;
+                }
+                intY_len += 1;
+            },
+            else => state = .m,
+        },
+    };
+    return total;
+}
diff --git a/day3/main.zig b/day3/part2.zig
similarity index 88%
rename from day3/main.zig
rename to day3/part2.zig
index 2e6f158..4203015 100644
--- a/day3/main.zig
+++ b/day3/part2.zig
@@ -19,27 +19,20 @@ const LookingFor = enum {
 var file_buf: [1024 * 1024]u8 = undefined; // The file do 20kB, I give it 1MB
 
 pub fn main() !void {
-    const time_start = std.time.microTimestamp();
-
     const file = try std.fs.cwd().openFile("day3/input", .{});
     defer file.close();
 
     const len = try file.readAll(&file_buf);
 
-    var total: u32 = 0;
-    var enable = true;
-    total += try parse(file_buf[0..len], &enable);
-
-    const time_end = std.time.microTimestamp();
-    print("Total time: {d}μs\n", .{time_end - time_start});
-    print("Total safe: {d}\n", .{total});
+    try std.testing.expectEqual(82857512, try parse(file_buf[0..len]));
 }
 
-fn parse(input: []const u8, enable: *bool) !u32 {
+fn parse(input: []const u8) !u32 {
     var state: LookingFor = .m_or_d;
     var total: u32 = 0;
     var intX_len: u8 = 0;
     var intY_len: u8 = 0;
+    var enable = true;
     var enable_buff: bool = true;
     for (input, 0..) |c, i| switch (state) {
         .m_or_d => switch (c) {
@@ -89,7 +82,7 @@ fn parse(input: []const u8, enable: *bool) !u32 {
         },
         .r_brace_do => switch (c) {
             ')' => {
-                enable.* = enable_buff;
+                enable = enable_buff;
                 enable_buff = true;
                 state = .m_or_d;
             },
@@ -108,7 +101,7 @@ fn parse(input: []const u8, enable: *bool) !u32 {
             ')' => {
                 state = .m_or_d;
                 if (intY_len > 0) {
-                    if (!enable.*) continue;
+                    if (!enable) continue;
                     const x = try std.fmt.parseInt(u32, input[i - (intX_len + intY_len + 1) .. i - intY_len - 1], 10);
                     const y = try std.fmt.parseInt(u32, input[i - intY_len .. i], 10);
                     total += x * y;
diff --git a/day4/part1.zig b/day4/part1.zig
index efc89cb..4c06825 100644
--- a/day4/part1.zig
+++ b/day4/part1.zig
@@ -55,15 +55,9 @@ const masks = [_][4][4]u8{
 };
 
 pub fn main() !void {
-    const time_start = std.time.microTimestamp();
-
     setMatrice('.');
     try fillMatrice();
-    const total = countMask();
-
-    const time_end = std.time.microTimestamp();
-    print("Total time: {d}μs\n", .{time_end - time_start});
-    print("Total: {d}\n", .{total});
+    try std.testing.expectEqual(2401, countMask());
 }
 
 fn evaluate(mask: [4][4]u8, sub: [4][4]u8) bool {
diff --git a/day4/part2.zig b/day4/part2.zig
index 357e122..3e08fb5 100644
--- a/day4/part2.zig
+++ b/day4/part2.zig
@@ -27,15 +27,9 @@ const masks = [_][3][3]u8{
 };
 
 pub fn main() !void {
-    const time_start = std.time.microTimestamp();
-
     setMatrice('.');
     try fillMatrice();
-    const total = countMask();
-
-    const time_end = std.time.microTimestamp();
-    print("Total time: {d}μs\n", .{time_end - time_start});
-    print("Total: {d}\n", .{total});
+    try std.testing.expectEqual(1822, countMask());
 }
 
 fn evaluate(mask: [3][3]u8, sub: [3][3]u8) bool {