Day 3 Part 2 WIP

day3/part2/main.cpp

@@ -1,43 +1,127 @@
 #include <iostream>
 #include <fstream>
 #include <vector>
+#include <algorithm>
 
 using namespace std;
 
-struct Command {
-    string direction;
-    int distance;
-};
-
 int main() {
-    cout << "Advent of Code 2021 - Day 2 Part 2" << endl;
+    cout << "Advent of Code 2021 - Day 3 Part 2" << endl;
 
-    int x, y, aim = 0;
+    vector<vector<char>> inputBits;
 
     ifstream filein("input");
-    vector<Command> inputCommands;
     for(string line; getline(filein, line);) {
-        int space = line.find(" ");
+        vector<char> bits;
-        inputCommands.push_back(Command {line.substr(0, space), stoi(line.substr(space+1))});
+        for(int i = 0; i < 12; i++) {
+            if (line[i] == '1') {
+                bits.push_back(1);
+            }
+            else {
+                bits.push_back(0);
+            }
+        }
+        inputBits.push_back(bits);
     }
 
-    for(Command cmd : inputCommands) {
+    vector<vector<char>> oxygen = inputBits;
-        if(cmd.direction == "forward") {
+
-            x += cmd.distance;
+    int x, greater = 0;
-            y += cmd.distance * aim;
+    while (oxygen.size() != 1) {
+        for(int i = 0; i < oxygen.size(); i++) {
+            if(oxygen[i][x] == 1) {
+                greater++;
+            }
         }
-        else if (cmd.direction == "down") {
+
-            aim += cmd.distance;
+        char matcher;
+        if(greater > (oxygen.size() / 2)) {
+            matcher = 1;
+            } else {
+            matcher = 0;
         }
-        else if(cmd.direction == "up") {
+
-            aim -= cmd.distance;
+        oxygen.erase(
+            remove_if(
+                oxygen.begin(),
+                oxygen.end(),
+                [x, matcher](vector<char> z) {
+                    if (z[x] != matcher) {
+                        return true;
+                    }
+                    return false;
+                }
+            ), oxygen.end()
+        );
+
+        x++;
+        greater = 0;
+    }
+
+    vector<vector<char>> co2 = inputBits;
+
+    x = 0;
+    greater = 0;
+
+    while (co2.size() != 1) {
+        for(int i = 0; i < co2.size(); i++) {
+            if(co2[i][x] == 0) {
+                greater++;
+            }
         }
-        else {
+
-            cout << "Uh I shouldn't get here in the for cmd loop" << endl;
+        char matcher;
+        if(greater > (co2.size() / 2)) {
+            matcher = 0;
+            } else {
+            matcher = 1;
+        }
+
+        co2.erase(
+            remove_if(
+                co2.begin(),
+                co2.end(),
+                [x, matcher](vector<char> z) {
+                    if (z[x] != matcher) {
+                        return true;
+                    }
+                    return false;
+                }
+            ), co2.end()
+        );
+
+        x++;
+        greater = 0;
+    }
+
+    for (auto c : oxygen) {
+        for (auto z : c) {
+            cout << +z;
+        }
+    }
+    cout << endl;
+
+    for (auto c : co2) {
+        for (auto z : c) {
+            cout << +z;
+        }
+    }
+    cout << endl;
+
+    unsigned int oxygen_final = 0;
+    unsigned int co2_final = 0;
+
+    for(int x = 0; x < 12; x++) {
+        if(oxygen[0][x] == 1) {
+            oxygen_final |= 1UL << 11 - x;
+        }
+        if(co2[0][x] == 1) {
+            co2_final |= 1UL << 11 - x;
         }
     }
 
-    cout << x * y << endl;
+    cout << oxygen_final << endl << co2_final << endl;
+    cout << oxygen_final * co2_final << endl;
 
     return 0;
 }