Day 8

Day8/part1.cpp

@@ -0,0 +1,93 @@
+#include <iostream>
+#include <string>
+
+using namespace std;
+
+int main(int argc, char* argv[])
+{
+    string line;
+    getline(cin, line);
+
+    int length = line.size();
+
+    int* forest = new int[length*length];
+    int in_y = 0;
+    do
+    {
+        for(int i = 0; i < length; i++)
+        {
+            forest[i+in_y*length] = line[i]-'0';
+        }
+        ++in_y;
+    } while(getline(cin, line));
+
+    bool* visible = new bool[length*length];
+    for(int i = 0; i < length*length; i++)
+    {
+        visible[i] = false;
+    }
+
+    for(int x = 0; x < length; x++)
+    {
+        //top down
+        int vis_height = -1;
+        for(int y = 0; y < length; y++)
+        {
+            if (forest[x+y*length] > vis_height)
+            {
+                vis_height = forest[x+y*length];
+                visible[x+y*length] = true;
+            }
+        }
+
+        //bottom up
+        vis_height = -1;
+        for(int y = length-1; y >= 0; y--)
+        {
+            if (forest[x+y*length] > vis_height)
+            {
+                vis_height = forest[x+y*length];
+                visible[x+y*length] = true;
+            }
+        }
+    }
+
+    for(int y = 0; y < length; y++)
+    {
+        //Left right
+        int vis_height = -1;
+        for(int x = 0; x < length; x++)
+        {
+            if (forest[x+y*length] > vis_height)
+            {
+                vis_height = forest[x+y*length];
+                visible[x+y*length] = true;
+            }
+        }
+
+        //Right left
+        vis_height = -1;
+        for(int x = length-1; x >= 0; x--)
+        {
+            if (forest[x+y*length] > vis_height)
+            {
+                vis_height = forest[x+y*length];
+                visible[x+y*length] = true;
+            }
+        }
+    }
+
+    int total_vis = 0;
+    for(int i = 0; i < length*length; i++)
+    {
+        if(visible[i])
+        {
+            ++total_vis;
+        }
+    }
+
+    cout << total_vis << endl;
+
+    delete[] visible;
+    delete[] forest;
+}

Day8/part2.cpp

@@ -0,0 +1,83 @@
+#include <iostream>
+#include <string>
+
+using namespace std;
+
+int main(int argc, char* argv[])
+{
+    string line;
+    getline(cin, line);
+
+    int length = line.size();
+
+    int* forest = new int[length*length];
+    int in_y = 0;
+    do
+    {
+        for(int i = 0; i < length; i++)
+        {
+            forest[i+in_y*length] = line[i]-'0';
+        }
+        ++in_y;
+    } while(getline(cin, line));
+
+    int best_vis = 0;
+    for(int y = 0; y < length; y++)
+    {
+        for(int x = 0; x < length; x++)
+        {
+            int north_vis = 0;
+            int south_vis = 0;
+            int west_vis = 0;
+            int east_vis = 0;
+            int cur_vis = forest[x+y*length];;
+
+            for(int j = y-1; j >= 0; j--)
+            {
+                north_vis++;
+                if (forest[x+j*length] >= cur_vis)
+                {
+                    break;
+                }
+            }
+
+            for(int j = y+1; j < length; j++)
+            {
+                south_vis++;
+                if (forest[x+j*length] >= cur_vis)
+                {
+                    break;
+                }
+            }
+
+            for(int i = x-1; i >= 0; i--)
+            {
+                west_vis++;
+                if (forest[i+y*length] >= cur_vis)
+                {
+                    break;
+                }
+            }
+
+            for(int i = x+1; i<length; i++)
+            {
+                east_vis++;
+                if(forest[i+y*length] >= cur_vis)
+                {
+                    break;
+                }
+            }
+
+            int total_vis = north_vis*south_vis*east_vis*west_vis;
+
+            if (total_vis > best_vis)
+            {
+                best_vis = total_vis;
+            }
+        }
+    }
+
+    cout << best_vis << endl;
+
+    delete[] forest;
+}