day 6

1 files changed, 71 insertions, 0 deletions

diff --git a/src/day-6/part-1.zig b/src/day-6/part-1.zig
new file mode 100644
index 0000000..9db35f3
--- /dev/null
+++ b/src/day-6/part-1.zig
@@ -0,0 +1,71 @@
+const std = @import("std");
+
+const problem = struct {n: std.ArrayList(u64), mult: bool};
+
+pub fn op(alloc: std.mem.Allocator, list: *std.ArrayList(problem), chunk: usize, count: u64, slice: []u8) !void {
+    if(slice[0] == '+' or slice[0] == '*'){
+        list.items[chunk].mult = slice[0] == '*';
+    } else {
+        const n: u64 = try std.fmt.parseInt(u64, slice, 10);
+
+        if(count == 0) {
+            var l = std.ArrayList(u64).init(alloc);
+            try l.append(n);
+            try list.append(problem{.n = l, .mult = false});
+        }
+        else try list.items[chunk].n.append(n);
+    }
+}
+
+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: [8000]u8 = undefined;
+
+    var list = std.ArrayList(problem).init(alloc);
+    defer list.deinit();
+    defer for(list.items) |v| v.n.deinit();
+
+    var count: u64 = 0;
+
+    while(try reader.readUntilDelimiterOrEof(&buffer, '\n')) |line| : (count += 1) {
+        var i: usize = 0;
+        var chunk: usize = 0;
+        while(i < line.len){
+            while(i < line.len and line[i] == ' ') : (i += 1){}
+
+            if(std.mem.indexOf(u8, line[i..], " ")) |ind| {
+                try op(alloc, &list, chunk, count, line[i..i + ind]);
+                i = i + ind;
+                chunk += 1;
+            } else {
+                if(line[i..].len != 0){
+                    try op(alloc, &list, chunk, count, line[i..]); 
+                }
+                break;
+            }
+        }
+    }
+
+    var total: u64 = 0;
+
+    for(list.items) |v| {
+        var n: u64 = 0;
+        if(v.mult){
+            n = 1;
+            for(v.n.items) |a| n *= a;
+        } else {
+            for(v.n.items) |a| n += a;
+        }
+        total += n;
+    }
+
+    std.debug.print("{d}\n", .{total});
+}