Add solution for 2016 Day 5

- Add Md5 algorithm to library
2026-08-15 15:24:22 +02:00
parent c228e8e230
commit bf12e141a6
5 changed files with 201 additions and 12 deletions
@@ -0,0 +1 @@
+abc
@@ -2,30 +2,60 @@

 namespace y2016::day05
 {
-  REGISTER_DAY(2016, Day05, std::vector<int>, int);
+  REGISTER_DAY(2016, Day05, std::string, std::string);

-  REGISTER_TEST_EXAMPLE(2016, Day05, ExampleInput, 1, 0);
-  REGISTER_TEST(2016, Day05, Input, 1, 0);
-  REGISTER_TEST_EXAMPLE(2016, Day05, ExampleInput, 2, 0);
-  REGISTER_TEST(2016, Day05, Input, 2, 0);
+  REGISTER_TEST(2016, Day05, Input, 1, "f97c354d");
+  REGISTER_TEST(2016, Day05, Input, 2, "863dde27");

  READ_INPUT(input)
  {
-    std::vector<int> vec;
    std::string str;
-    while (getline(input, str))
-    {
-    }
-    return vec;
+    getline(input, str);
+    return str;
  }

  OUTPUT1(input)
  {
-    return 0;
+    int i = 0;
+    std::string result;
+    while (true)
+    {
+      std::string str = input + std::to_string(i);
+      std::string s = Md5::Hash(str);
+      if (Helper::StartsWith(s, "00000"))
+      {
+        result.push_back(s[5]);
+        if (result.size() == 8)
+          return result;
+      }
+      i++;
+    }
+    return "";
  }

  OUTPUT2(input)
  {
-    return 0;
+    int i = 0;
+    std::string result{"XXXXXXXX"};
+    int replacements = 0;
+    for (int i = 0;; i++)
+    {
+      std::string str = input + std::to_string(i);
+      std::string s = Md5::Hash(str);
+      if (Helper::StartsWith(s, "00000"))
+      {
+        if (s[5] < '0' || s[5] > '7')
+          continue;
+
+        if (result[s[5] - '0'] == 'X')
+        {
+          result[s[5] - '0'] = s[6];
+          replacements++;
+        }
+        if (replacements == 8)
+          return result;
+      }
+    }
+    return "";
  }
 }
@@ -30,6 +30,7 @@
 #include "common/lib/Json.h"
 #include "common/lib/Mapper.h"
 #include "common/lib/Math.h"
+#include "common/lib/Md5.h"
 #include "common/lib/Timer.h"

 #define TERM_RED "\x1B[31m"
@@ -0,0 +1,140 @@
+#include "common/lib/Md5.h"
+
+#include <array>
+#include <cstring>
+#include <iomanip>
+#include <iostream>
+
+uint32_t Md5::BytesToUint32(uint8_t* data)
+{
+  return ((uint32_t)data[3] << 24) | ((uint32_t)data[2] << 16) | ((uint32_t)data[1] << 8) | (uint32_t)data[0];
+}
+
+uint32_t Md5::LeftRotate(uint32_t x, uint32_t n)
+{
+  return (x << n) | (x >> (32 - n));
+}
+
+void Md5::Transform(uint8_t* data, uint32_t& a0, uint32_t& b0, uint32_t& c0, uint32_t& d0)
+{
+  // clang-format off
+  const static std::array<uint32_t, 64> K
+  {
+    0xd76aa478, 0xe8c7b756, 0x242070db, 0xc1bdceee,
+    0xf57c0faf, 0x4787c62a, 0xa8304613, 0xfd469501,
+    0x698098d8, 0x8b44f7af, 0xffff5bb1, 0x895cd7be,
+    0x6b901122, 0xfd987193, 0xa679438e, 0x49b40821,
+    0xf61e2562, 0xc040b340, 0x265e5a51, 0xe9b6c7aa,
+    0xd62f105d, 0x02441453, 0xd8a1e681, 0xe7d3fbc8,
+    0x21e1cde6, 0xc33707d6, 0xf4d50d87, 0x455a14ed,
+    0xa9e3e905, 0xfcefa3f8, 0x676f02d9, 0x8d2a4c8a,
+    0xfffa3942, 0x8771f681, 0x6d9d6122, 0xfde5380c,
+    0xa4beea44, 0x4bdecfa9, 0xf6bb4b60, 0xbebfbc70,
+    0x289b7ec6, 0xeaa127fa, 0xd4ef3085, 0x04881d05,
+    0xd9d4d039, 0xe6db99e5, 0x1fa27cf8, 0xc4ac5665,
+    0xf4292244, 0x432aff97, 0xab9423a7, 0xfc93a039,
+    0x655b59c3, 0x8f0ccc92, 0xffeff47d, 0x85845dd1,
+    0x6fa87e4f, 0xfe2ce6e0, 0xa3014314, 0x4e0811a1,
+    0xf7537e82, 0xbd3af235, 0x2ad7d2bb, 0xeb86d391
+  };
+  const static std::array<uint32_t, 64> S
+  {
+    7, 12, 17, 22, 7, 12, 17, 22, 7, 12, 17, 22, 7, 12, 17, 22,
+    5,  9, 14, 20, 5,  9, 14, 20, 5,  9, 14, 20, 5,  9, 14, 20,
+    4, 11, 16, 23, 4, 11, 16, 23, 4, 11, 16, 23, 4, 11, 16, 23,
+    6, 10, 15, 21, 6, 10, 15, 21, 6, 10, 15, 21, 6, 10, 15, 21
+  };
+  // clang-format on
+
+  uint32_t A = a0;
+  uint32_t B = b0;
+  uint32_t C = c0;
+  uint32_t D = d0;
+
+  for (int i = 0; i < 64; i++)
+  {
+    uint32_t F;
+    uint32_t g;
+    if (i < 16)
+    {
+      F = (B & C) | ((~B) & D);
+      g = i;
+    }
+    else if (i < 32)
+    {
+      F = (D & B) | ((~D) & C);
+      g = (5 * i + 1) % 16;
+    }
+    else if (i < 48)
+    {
+      F = B ^ C ^ D;
+      g = (3 * i + 5) % 16;
+    }
+    else
+    {
+      F = C ^ (B | (~D));
+      g = (7 * i) % 16;
+    }
+    F = F + A + K[i] + BytesToUint32(data + g * 4);
+    A = D;
+    D = C;
+    C = B;
+    B = B + LeftRotate(F, S[i]);
+  }
+  a0 += A;
+  b0 += B;
+  c0 += C;
+  d0 += D;
+}
+
+void Md5::PrintUint32(std::ostream& os, uint32_t n)
+{
+  os << std::hex;
+  os << std::setw(2) << std::setfill('0') << (n & 0xff);
+  os << std::setw(2) << std::setfill('0') << ((n >> 8) & 0xff);
+  os << std::setw(2) << std::setfill('0') << ((n >> 16) & 0xff);
+  os << std::setw(2) << std::setfill('0') << ((n >> 24) & 0xff);
+  os << std::dec;
+}
+
+std::string Md5::Hash(std::string str)
+{
+  str += 0x80;
+
+  uint32_t a0 = 0x67452301;
+  uint32_t b0 = 0xefcdab89;
+  uint32_t c0 = 0x98badcfe;
+  uint32_t d0 = 0x10325476;
+
+  uint64_t size = str.size();
+  uint64_t bytesToAdd = (64 + 56 - (size % 64)) % 64;
+
+  // std::cout << str.size() << " " << bytesToAdd << std::endl;
+  int loops = (size + bytesToAdd + 8) / 64;
+  if ((size + bytesToAdd + 8) % 64 != 0)
+    loops++;
+  uint64_t offset = 0;
+  for (int i = 0; i < loops - 1; i++)
+  {
+    Transform((uint8_t*)(str.c_str() + offset), a0, b0, c0, d0);
+    offset += 64;
+  }
+
+  uint8_t data[64];
+  std::memset(data, 0x0, 64);
+  if (str.size() >= offset)
+    std::memcpy(data, str.c_str() + offset, str.size() - offset);
+  for (int i = 0; i < 8; i++)
+  {
+    data[56 + i] = (((str.size() - 1) * 8) >> (i * 8)) & 0xff;
+  }
+
+  Transform(data, a0, b0, c0, d0);
+
+  std::stringstream ss{};
+  PrintUint32(ss, a0);
+  PrintUint32(ss, b0);
+  PrintUint32(ss, c0);
+  PrintUint32(ss, d0);
+  return ss.str();
+}
@@ -0,0 +1,17 @@
+#pragma once
+
+#include <stdint.h>
+
+#include <string>
+
+class Md5
+{
+public:
+  static std::string Hash(std::string str);
+
+private:
+  static uint32_t BytesToUint32(uint8_t* data);
+  static uint32_t LeftRotate(uint32_t x, uint32_t n);
+  static void Transform(uint8_t* data, uint32_t& a0, uint32_t& b0, uint32_t& c0, uint32_t& d0);
+  static void PrintUint32(std::ostream& os, uint32_t n);
+};