solve up to day 7

1 files changed, 100 insertions, 0 deletions

diff --git a/src/day06.zig b/src/day06.zig
new file mode 100644
index 0000000..4105800
--- /dev/null
+++ b/src/day06.zig
@@ -0,0 +1,100 @@
+const std = @import("std");
+const print = std.debug.print;
+
+pub fn solve(part: []u8, reader: *std.Io.Reader, allocator: std.mem.Allocator) !void {
+    if (std.mem.eql(u8, part, "1")) {
+        try part1(reader, allocator);
+    } else {
+        try part2(reader, allocator);
+    }
+}
+
+fn part1(reader: *std.Io.Reader, allocator: std.mem.Allocator) !void {
+    var output: usize = 0;
+    var problems = try std.ArrayList(std.ArrayList(usize)).initCapacity(allocator, 0);
+    defer problems.deinit(allocator);
+
+    while (reader.takeDelimiter('\n')) |line| {
+        if (line == null) {
+            break;
+        }
+
+        var split = std.mem.splitScalar(u8, line.?, ' ');
+        var n: usize = 0;
+        while(split.next()) |part| {
+            if (part.len > 0){
+
+                if (part[0] == '+') {
+                    for(problems.items[n].items) |number| {
+                        output += number;
+                    }
+                    problems.items[n].deinit(allocator);
+                } else if (part[0] == '*') {
+                    var tmp: usize = 1;
+                    for(problems.items[n].items) |number| {
+                        tmp *= number;
+                    }
+                    output += tmp;
+                    problems.items[n].deinit(allocator);
+                } else {
+                    const number = try std.fmt.parseInt(usize, part, 10);
+
+                    if (n >= problems.items.len) {
+                        try  problems.append(allocator, try std.ArrayList(usize).initCapacity(allocator, 0));
+                    }
+
+                    try problems.items[n].append(allocator, number);
+                }
+
+                n += 1;
+            }
+        }
+
+    } else |_| {}
+
+    print("{d}\n", .{output});
+}
+
+
+fn part2(reader: *std.Io.Reader, allocator: std.mem.Allocator) !void {
+    var output: usize = 0;
+    var problems = try std.ArrayList([]u8).initCapacity(allocator, 0);
+    defer problems.deinit(allocator);
+
+    while (reader.takeDelimiter('\n')) |line| {
+        if (line == null) {
+            break;
+        }
+
+        try problems.append(allocator, line.?);
+    } else |_| {}
+
+
+    var n: usize = 0;
+    var accum: usize = 1;
+    var operator = problems.items[problems.items.len - 1][0];
+    while(n < problems.items[0].len) {
+        var number: usize = 0;
+        for (0..problems.items.len - 1) |i| {
+            if (problems.items[i][n] != ' ') {
+                number *= 10;
+                number += problems.items[i][n] - '0';
+            }
+        }
+
+        n += 1;
+        if (number == 0) {
+            if (operator == '*') {
+                output += accum;
+            }
+            operator = problems.items[problems.items.len - 1][n];
+            accum = 1;
+        } else if (operator == '+') {
+            output += number;
+        } else {
+            accum *= number;
+        }
+    }
+
+    print("{d}\n", .{output});
+}