solve up to day 7

1 files changed, 107 insertions, 0 deletions

diff --git a/src/day05.zig b/src/day05.zig
new file mode 100644
index 0000000..2f971f9
--- /dev/null
+++ b/src/day05.zig
@@ -0,0 +1,107 @@
+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);
+    }
+}
+
+const Range = struct { start: usize, end: usize };
+
+fn part1(reader: *std.Io.Reader, allocator: std.mem.Allocator) !void {
+    var output: usize = 0;
+
+    var ranges = try std.ArrayList(Range).initCapacity(allocator, 0);
+    defer ranges.deinit(allocator);
+
+    while (reader.takeDelimiter('\n')) |line| {
+        if (line == null or line.?.len == 0){
+            break;
+        }
+
+        var split = std.mem.splitScalar(u8, line.?, '-');
+        const start = try std.fmt.parseInt(usize, split.next().?, 10);
+        const end = try std.fmt.parseInt(usize, split.next().?, 10);
+
+        try ranges.append(allocator, Range{ .start=start, .end=end});
+
+    } else |_| {}
+
+    while (reader.takeDelimiter('\n')) |line| {
+        if (line == null) {
+            break;
+        }
+
+        const id = try std.fmt.parseInt(usize, line.?, 10);
+
+        for(ranges.items) |range| {
+            if (id >= range.start and id <= range.end) {
+                output += 1;
+                break;
+            }
+        }
+
+    } else |_| {}
+
+    print("{d}\n", .{output});
+}
+
+fn cmp(_: void, a: Range, b: Range) bool {
+        return a.start < b.start;
+}
+
+fn part2(reader: *std.Io.Reader, allocator: std.mem.Allocator) !void {
+    var output: usize = 0;
+
+    var ranges = try std.ArrayList(Range).initCapacity(allocator, 0);
+    defer ranges.deinit(allocator);
+
+    while (reader.takeDelimiter('\n')) |line| {
+        if (line == null or line.?.len == 0){
+            break;
+        }
+
+        var split = std.mem.splitScalar(u8, line.?, '-');
+        const start = try std.fmt.parseInt(usize, split.next().?, 10);
+        const end = try std.fmt.parseInt(usize, split.next().?, 10);
+
+        try ranges.append(allocator, Range{ .start=start, .end=end});
+
+    } else |_| {}
+
+
+    std.mem.sort(Range,ranges.items, {}, cmp);
+
+    var more = try std.ArrayList(Range).initCapacity(allocator, 0);
+    defer more.deinit(allocator);
+
+    outer: for (ranges.items) |r| {
+
+        const start = r.start;
+        const end = r.end;
+
+        for (more.items) |*range| {
+            if (start >= range.start and start <= range.end) {
+                if (end > range.end){
+                    range.end = end;
+                }
+                continue :outer;
+            } else if (start < range.start and end >= range.start) {
+                range.start = start;
+                continue :outer;
+            }
+        }
+
+        try more.append(allocator, Range{ .start=start, .end=end});
+
+    }
+
+    for (more.items) |range| {
+        output += range.end - range.start + 1;
+    }
+
+    print("{d}\n", .{output});
+}