Implement day 19 part 1.

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) {