day 2

3 files changed, 114 insertions, 0 deletions

diff --git a/src/day-2/input.txt b/src/day-2/input.txt
new file mode 100644
index 0000000..c893dde
--- /dev/null
+++ b/src/day-2/input.txt
@@ -0,0 +1 @@
+18623-26004,226779-293422,65855-88510,868-1423,248115026-248337139,903911-926580,97-121,67636417-67796062,24-47,6968-10197,193-242,3769-5052,5140337-5233474,2894097247-2894150301,979582-1016336,502-646,9132195-9191022,266-378,58-91,736828-868857,622792-694076,6767592127-6767717303,2920-3656,8811329-8931031,107384-147042,941220-969217,3-17,360063-562672,7979763615-7979843972,1890-2660,23170346-23308802
diff --git a/src/day-2/part-1.zig b/src/day-2/part-1.zig
new file mode 100644
index 0000000..ce3e1f5
--- /dev/null
+++ b/src/day-2/part-1.zig
@@ -0,0 +1,54 @@
+const std = @import("std");
+
+pub fn repeats(num: u64) !bool {
+    var buf: [20]u8 = undefined;
+
+    const str = try std.fmt.bufPrint(&buf, "{}", .{num});
+    if(@mod(str.len, 2) == 1) return false; 
+
+    for(0..str.len/2) |find| {
+        const bind = find + str.len/2;
+        if(str[find] != str[bind]) return false;
+        //std.debug.print("{} {c}, {} {c}\n", .{find, str[find], bind, str[bind]});
+
+    }
+
+    return true;
+}
+
+pub fn main() !void {
+    //var gpa = std.heap.GeneralPurposeAllocator(.{}){};
+    //defer gpa.deinit();
+    //const alloc = gpa.allocator();
+    
+    const path = "input.txt";
+    const fp = try std.fs.cwd().openFile(path, .{.mode = std.fs.File.OpenMode.read_only});
+    defer fp.close();
+    var reader = fp.reader();
+
+    var buffer: [256]u8 = undefined;
+
+    var total: u64 = 0;
+
+    while(try reader.readUntilDelimiterOrEof(&buffer, ',')) |l| {
+        var line = l;
+        if(line[line.len - 1] == '\n') {
+            line = line[0 .. line.len - 1];
+        }
+
+        if(std.mem.indexOf(u8, line, "-")) |ind| {
+            const start = try std.fmt.parseInt(u64, line[0 .. ind], 10);
+            const end = try std.fmt.parseInt(u64, line[ind + 1 ..], 10);
+
+            //std.debug.print("{d} - {d}\n", .{start, end});
+
+            for(start .. end + 1) |n| {
+                if(try repeats(n)){
+                    total += n;
+                    //std.debug.print("{}\n", .{n});
+                }
+            }
+        }
+    }
+    std.debug.print("{d}\n", .{total});
+}
diff --git a/src/day-2/part-2.zig b/src/day-2/part-2.zig
new file mode 100644
index 0000000..ce61ab2
--- /dev/null
+++ b/src/day-2/part-2.zig
@@ -0,0 +1,59 @@
+const std = @import("std");
+
+pub fn repeats(num: u64) !bool {
+    var buf: [20]u8 = undefined;
+
+    const str = try std.fmt.bufPrint(&buf, "{}", .{num});
+
+    for(1 .. str.len) |window| {
+        if(@mod(str.len, window) == 0){
+            const match = str[0 .. window];
+            var i: usize = 0;
+            while(i < str.len) : (i += window) {
+                if(!std.mem.eql(u8, match, str[i .. i + window])){
+                    break;
+                }
+            }
+            if(i == str.len) return true;
+        }
+    } 
+
+    return false;
+}
+
+pub fn main() !void {
+    //var gpa = std.heap.GeneralPurposeAllocator(.{}){};
+    //defer gpa.deinit();
+    //const alloc = gpa.allocator();
+    
+    const path = "input.txt";
+    const fp = try std.fs.cwd().openFile(path, .{.mode = std.fs.File.OpenMode.read_only});
+    defer fp.close();
+    var reader = fp.reader();
+
+    var buffer: [256]u8 = undefined;
+
+    var total: u64 = 0;
+
+    while(try reader.readUntilDelimiterOrEof(&buffer, ',')) |l| {
+        var line = l;
+        if(line[line.len - 1] == '\n') {
+            line = line[0 .. line.len - 1];
+        }
+
+        if(std.mem.indexOf(u8, line, "-")) |ind| {
+            const start = try std.fmt.parseInt(u64, line[0 .. ind], 10);
+            const end = try std.fmt.parseInt(u64, line[ind + 1 ..], 10);
+
+            //std.debug.print("{d} - {d}\n", .{start, end});
+
+            for(start .. end + 1) |n| {
+                if(try repeats(n)){
+                    total += n;
+                    //std.debug.print("{}\n", .{n});
+                }
+            }
+        }
+    }
+    std.debug.print("{d}\n", .{total});
+}