Implement day 05.

2019/CMakeLists.txt

@@ -12,7 +12,7 @@ add_executable(runner src/runner.cpp)
 target_compile_features(runner PUBLIC cxx_std_17)
 target_link_libraries(runner AoCSolutions)
 
-add_executable(unit_tests tests/test_solutions.cpp)
+add_executable(unit_tests tests/test_solutions.cpp tests/test_intcode.cpp)
 target_compile_features(unit_tests PUBLIC cxx_std_17)
 target_link_libraries(unit_tests AoCSolutions GTest::GTest GTest::Main)
 target_compile_definitions(unit_tests PRIVATE "TEST_SAMPLES_DIR=\"${CMAKE_SOURCE_DIR}/tests/samples\"")

2019/inputs/05.txt

@@ -0,0 +1 @@
+3,225,1,225,6,6,1100,1,238,225,104,0,1102,27,28,225,1,113,14,224,1001,224,-34,224,4,224,102,8,223,223,101,7,224,224,1,224,223,223,1102,52,34,224,101,-1768,224,224,4,224,1002,223,8,223,101,6,224,224,1,223,224,223,1002,187,14,224,1001,224,-126,224,4,224,102,8,223,223,101,2,224,224,1,224,223,223,1102,54,74,225,1101,75,66,225,101,20,161,224,101,-54,224,224,4,224,1002,223,8,223,1001,224,7,224,1,224,223,223,1101,6,30,225,2,88,84,224,101,-4884,224,224,4,224,1002,223,8,223,101,2,224,224,1,224,223,223,1001,214,55,224,1001,224,-89,224,4,224,102,8,223,223,1001,224,4,224,1,224,223,223,1101,34,69,225,1101,45,67,224,101,-112,224,224,4,224,102,8,223,223,1001,224,2,224,1,223,224,223,1102,9,81,225,102,81,218,224,101,-7290,224,224,4,224,1002,223,8,223,101,5,224,224,1,223,224,223,1101,84,34,225,1102,94,90,225,4,223,99,0,0,0,677,0,0,0,0,0,0,0,0,0,0,0,1105,0,99999,1105,227,247,1105,1,99999,1005,227,99999,1005,0,256,1105,1,99999,1106,227,99999,1106,0,265,1105,1,99999,1006,0,99999,1006,227,274,1105,1,99999,1105,1,280,1105,1,99999,1,225,225,225,1101,294,0,0,105,1,0,1105,1,99999,1106,0,300,1105,1,99999,1,225,225,225,1101,314,0,0,106,0,0,1105,1,99999,1007,677,677,224,102,2,223,223,1005,224,329,101,1,223,223,1108,226,677,224,1002,223,2,223,1005,224,344,101,1,223,223,1008,677,677,224,102,2,223,223,1005,224,359,101,1,223,223,8,226,677,224,1002,223,2,223,1006,224,374,101,1,223,223,108,226,677,224,1002,223,2,223,1006,224,389,1001,223,1,223,1107,226,677,224,102,2,223,223,1005,224,404,1001,223,1,223,7,226,677,224,1002,223,2,223,1005,224,419,101,1,223,223,1107,677,226,224,102,2,223,223,1006,224,434,1001,223,1,223,1107,226,226,224,1002,223,2,223,1006,224,449,101,1,223,223,1108,226,226,224,1002,223,2,223,1005,224,464,101,1,223,223,8,677,226,224,102,2,223,223,1005,224,479,101,1,223,223,8,226,226,224,1002,223,2,223,1006,224,494,1001,223,1,223,1007,226,677,224,1002,223,2,223,1006,224,509,1001,223,1,223,108,226,226,224,1002,223,2,223,1006,224,524,1001,223,1,223,1108,677,226,224,102,2,223,223,1006,224,539,101,1,223,223,1008,677,226,224,102,2,223,223,1006,224,554,101,1,223,223,107,226,677,224,1002,223,2,223,1006,224,569,101,1,223,223,107,677,677,224,102,2,223,223,1006,224,584,101,1,223,223,7,677,226,224,102,2,223,223,1005,224,599,101,1,223,223,1008,226,226,224,1002,223,2,223,1005,224,614,1001,223,1,223,107,226,226,224,1002,223,2,223,1005,224,629,101,1,223,223,7,226,226,224,102,2,223,223,1006,224,644,1001,223,1,223,1007,226,226,224,102,2,223,223,1006,224,659,101,1,223,223,108,677,677,224,102,2,223,223,1005,224,674,1001,223,1,223,4,223,99,226

2019/src/day05.cpp

@@ -1,10 +1,15 @@
 #include <iostream>
 #include "days.hpp"
+#include "utils.hpp"
 
 void aoc2019::day05_part1(std::istream &input, std::ostream &output) {
-	output << "Not implemented\n";
+    auto program = read_intcode(input);
+    auto result = aoc2019::run_intcode(program, { 1 });
+	output << result.back() << std::endl;
 }
 
 void aoc2019::day05_part2(std::istream &input, std::ostream &output) {
-	output << "Not implemented\n";
+    auto program = read_intcode(input);
+    auto result = run_intcode(program, { 5 });
+    output << result.back() << std::endl;
 }

2019/src/utils.cpp

@@ -1,3 +1,4 @@
+#include <iostream>
 #include "utils.hpp"
 
 std::string_view aoc2019::strtok(std::string_view &str, char token) {
@@ -10,3 +11,105 @@ std::string_view aoc2019::strtok(std::string_view &str, char token) {
     }
     return next;
 }
+
+std::vector<int> aoc2019::run_intcode(std::vector<int> &program, std::deque<int> inputs) {
+    std::vector<int> outputs{};
+    int ip = 0;
+    auto interpret_value = [&program, &ip](int pos) {
+        bool immediate = false;
+        switch (pos) {
+            case 1:
+                immediate = program[ip] / 100 % 10;
+                break;
+            case 2:
+                immediate = program[ip] / 1000 % 10;
+                break;
+
+            case 3:
+                immediate = program[ip] / 10000 % 10;
+                break;
+
+            default:
+                throw std::out_of_range("Invalid position");
+        }
+
+        if (immediate) {
+            return program[ip + pos];
+        } else {
+            return program[program[ip + pos]];
+        }
+    };
+
+    while (ip < program.size()) {
+        switch (program[ip] % 100) {
+            case 1:
+                program[program[ip + 3]] = interpret_value(1) + interpret_value(2);
+                ip += 4;
+                break;
+
+            case 2:
+                program[program[ip + 3]] = interpret_value(1) * interpret_value(2);
+                ip += 4;
+                break;
+
+            case 3:
+                if (inputs.empty()) {
+                    throw std::out_of_range("No inputs left");
+                }
+                program[program[ip + 1]] = inputs.front();
+                inputs.pop_front();
+                ip += 2;
+                break;
+
+            case 4:
+                outputs.push_back(interpret_value(1));
+                ip += 2;
+                break;
+
+            case 5: // Jump if non-zero
+                if (interpret_value(1)) {
+                    ip = interpret_value(2);
+                } else {
+                    ip += 3;
+                }
+                break;
+
+            case 6: // Jump if zero
+                if (!interpret_value(1)) {
+                    ip = interpret_value(2);
+                } else {
+                    ip += 3;
+                }
+                break;
+
+            case 7: // equality
+                program[program[ip + 3]] = interpret_value(1) < interpret_value(2);
+                ip += 4;
+                break;
+
+            case 8: // less than
+                program[program[ip + 3]] = interpret_value(1) == interpret_value(2) ? 1 : 0;
+                ip += 4;
+                break;
+
+            case 99:
+                return outputs;
+
+            default:
+                char buffer[30];
+                std::snprintf(buffer, sizeof(buffer), "Invalid opcode: %d", program[ip]);
+
+                throw std::domain_error(buffer);
+        }
+    }
+    throw std::out_of_range("Program read out of bounds");
+}
+
+std::vector<int> aoc2019::read_intcode(std::istream &input) {
+    std::vector<int> program{};
+    for (int current; input >> current; input.ignore()) {
+        program.push_back(current);
+    }
+
+    return program;
+}

2019/src/utils.hpp

@@ -1,22 +1,29 @@
 #pragma once
 
 #include <charconv>
+#include <deque>
 #include <functional>
+#include <iosfwd>
 #include <string_view>
+#include <vector>
 
 namespace aoc2019 {
 
     template<typename T>
-    inline std::from_chars_result from_chars(std::string_view str, T& value) {
+    inline std::from_chars_result from_chars(std::string_view str, T &value) {
         return std::from_chars(str.data(), str.data() + str.size(), value);
     }
 
     template<typename T>
-    void combine_hash(std::size_t& seed, const T& o) {
+    void combine_hash(std::size_t &seed, const T &o) {
         // Algorithm taken from boost::combine_hash.
         std::hash<T> hash{};
         seed ^= hash(o) + 0x9e3779b9 + (seed << 6) + (seed >> 2);
     }
 
     std::string_view strtok(std::string_view &str, char token = ',');
+
+    std::vector<int> read_intcode(std::istream &input);
+
+    std::vector<int> run_intcode(std::vector<int> &program, std::deque<int> inputs = {});
 }

2019/tests/test_intcode.cpp

@@ -0,0 +1,54 @@
+#include <gtest/gtest.h>
+#include "utils.hpp"
+
+using aoc2019::run_intcode;
+
+auto run_program(std::vector<int> program, std::deque<int> input) {
+    return run_intcode(program, std::move(input));
+}
+
+TEST(Intcode, TestPositionEquality) {
+    const std::vector<int> program = {3, 9, 8, 9, 10, 9, 4, 9, 99, -1, 8};
+
+    ASSERT_EQ(1, run_program(program, {8}).front());
+    ASSERT_EQ(0, run_program(program, {9}).front());
+}
+
+TEST(Intcode, TestPositionLess) {
+    const std::vector<int> program = {3, 9, 7, 9, 10, 9, 4, 9, 99, -1, 8};
+
+    ASSERT_EQ(1, run_program(program, {7}).front());
+    ASSERT_EQ(0, run_program(program, {9}).front());
+}
+
+TEST(Intcode, TestImmediateEquality) {
+    const std::vector<int> program = {3, 3, 1108, -1, 8, 3, 4, 3, 99};
+
+    ASSERT_EQ(1, run_program(program, {8}).front());
+    ASSERT_EQ(0, run_program(program, {9}).front());
+}
+
+TEST(Intcode, TestImmediateLess) {
+    const std::vector<int> program = {3, 3, 1107, -1, 8, 3, 4, 3, 99};
+
+    ASSERT_EQ(1, run_program(program, {7}).front());
+    ASSERT_EQ(0, run_program(program, {9}).front());
+}
+
+TEST(Intcode, TestComplicatedConditional) {
+    const std::vector<int> program = {3, 21, 1008, 21, 8, 20, 1005, 20, 22, 107, 8, 21, 20, 1006, 20, 31,
+                                      1106, 0, 36, 98, 0, 0, 1002, 21, 125, 20, 4, 20, 1105, 1, 46, 104,
+                                      999, 1105, 1, 46, 1101, 1000, 1, 20, 4, 20, 1105, 1, 46, 98, 99};
+    auto pcopy = program;
+
+    auto output = run_intcode(pcopy, {7});
+    ASSERT_EQ(999, output.front());
+
+    pcopy = program;
+    output = run_intcode(pcopy, {9});
+    ASSERT_EQ(1001, output.front());
+
+    pcopy = program;
+    output = run_intcode(pcopy, {8});
+    ASSERT_EQ(1000, output.front());
+}