From 73898e1cb73dbd8745fc5567178d5337133be407 Mon Sep 17 00:00:00 2001
From: Bert Peters <bert@bertptrs.nl>
Date: Thu, 19 Dec 2019 20:24:34 +0100
Subject: [PATCH] Implement day 19 part 1.

---
 2019/inputs/19     |  1 +
 2019/src/day19.cpp | 50 +++++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 50 insertions(+), 1 deletion(-)
 create mode 100644 2019/inputs/19

diff --git a/2019/inputs/19 b/2019/inputs/19
new file mode 100644
index 0000000..1ce9811
--- /dev/null
+++ b/2019/inputs/19
@@ -0,0 +1 @@
+109,424,203,1,21101,0,11,0,1105,1,282,21101,18,0,0,1105,1,259,2101,0,1,221,203,1,21102,1,31,0,1105,1,282,21101,0,38,0,1106,0,259,21002,23,1,2,22101,0,1,3,21101,0,1,1,21102,1,57,0,1106,0,303,2102,1,1,222,21001,221,0,3,20102,1,221,2,21101,0,259,1,21101,80,0,0,1106,0,225,21101,0,23,2,21102,91,1,0,1106,0,303,1201,1,0,223,20101,0,222,4,21101,0,259,3,21102,1,225,2,21102,1,225,1,21102,1,118,0,1105,1,225,20102,1,222,3,21101,0,87,2,21101,133,0,0,1106,0,303,21202,1,-1,1,22001,223,1,1,21101,0,148,0,1105,1,259,2101,0,1,223,20102,1,221,4,21002,222,1,3,21101,0,9,2,1001,132,-2,224,1002,224,2,224,1001,224,3,224,1002,132,-1,132,1,224,132,224,21001,224,1,1,21102,1,195,0,106,0,109,20207,1,223,2,21001,23,0,1,21102,1,-1,3,21101,0,214,0,1106,0,303,22101,1,1,1,204,1,99,0,0,0,0,109,5,2102,1,-4,249,21201,-3,0,1,22101,0,-2,2,21202,-1,1,3,21102,250,1,0,1106,0,225,21202,1,1,-4,109,-5,2106,0,0,109,3,22107,0,-2,-1,21202,-1,2,-1,21201,-1,-1,-1,22202,-1,-2,-2,109,-3,2105,1,0,109,3,21207,-2,0,-1,1206,-1,294,104,0,99,21202,-2,1,-2,109,-3,2105,1,0,109,5,22207,-3,-4,-1,1206,-1,346,22201,-4,-3,-4,21202,-3,-1,-1,22201,-4,-1,2,21202,2,-1,-1,22201,-4,-1,1,22102,1,-2,3,21102,1,343,0,1106,0,303,1106,0,415,22207,-2,-3,-1,1206,-1,387,22201,-3,-2,-3,21202,-2,-1,-1,22201,-3,-1,3,21202,3,-1,-1,22201,-3,-1,2,21201,-4,0,1,21102,384,1,0,1105,1,303,1106,0,415,21202,-4,-1,-4,22201,-4,-3,-4,22202,-3,-2,-2,22202,-2,-4,-4,22202,-3,-2,-3,21202,-4,-1,-2,22201,-3,-2,1,21202,1,1,-4,109,-5,2106,0,0
diff --git a/2019/src/day19.cpp b/2019/src/day19.cpp
index aa2248c..e1ee29a 100644
--- a/2019/src/day19.cpp
+++ b/2019/src/day19.cpp
@@ -1,8 +1,56 @@
 #include <iostream>
+#include <cassert>
 #include "days.hpp"
+#include "utils.hpp"
+
+namespace {
+    bool bounds_check(aoc2019::IntCodeComputer computer, std::int64_t x, std::int64_t y) {
+        std::deque<std::int64_t> output_buffer;
+        computer.connectOutput(output_buffer);
+
+        computer.sendInput(x);
+        computer.sendInput(y);
+
+        computer.run();
+        assert(computer.isTerminated());
+        assert(!output_buffer.empty());
+
+        return output_buffer.front();
+    }
+}
 
 void aoc2019::day19_part1(std::istream &input, std::ostream &output) {
-	output << "Not implemented\n";
+    IntCodeComputer computer(input);
+
+    std::int64_t covered = 0;
+    int last_width = 1;
+    int last_start = 0;
+    for (std::int64_t y = 0; y < 50; ++y) {
+        auto x = last_start;
+
+        while (!bounds_check(computer, x, y) && x < 50) {
+            ++x;
+        }
+
+        if (x == 50) break;
+
+        last_start = x;
+        x += last_width - 1;
+
+        if (!bounds_check(computer, x, y)) {
+            std::cerr << x << "," << y << "," << covered << std::endl;
+            throw std::logic_error("Assumption false");
+        }
+
+        while (bounds_check(computer, x, y) && x < 50) {
+            ++x;
+        }
+
+        last_width = x - last_start;
+        covered += last_width;
+    }
+
+    output << covered << std::endl;
 }
 
 void aoc2019::day19_part2(std::istream &input, std::ostream &output) {