Files
contests/advent_of_code/2022/8/main.cpp

97 lines
2.4 KiB
C++

#include <bits/stdc++.h>
using namespace std;
int main(){
ifstream input_file("input.txt");
string line;
vector<vector<int>> tree_height_map;
while(getline(input_file, line)){
vector<int> acc;
for(char c : line){
acc.push_back(c - '0');
}
tree_height_map.push_back(acc);
}
size_t WIDTH = tree_height_map.at(0).size();
size_t HEIGHT = tree_height_map.size();
vector<vector<bool>> spotted_trees;
vector<bool> dummy(WIDTH, false);
for(size_t i = 0; i < HEIGHT; ++i){
spotted_trees.push_back(dummy);
}
int result = 0;
// Now check from all directions
// Left to right first
for(size_t i = 0; i < HEIGHT; ++i){
int highest_tree = -1;
for(size_t j = 0; j < WIDTH; ++j){
if(tree_height_map[i][j] > highest_tree){
highest_tree = tree_height_map[i][j];
if(!spotted_trees[i][j]){
result++;
spotted_trees[i][j] = true;
}
}
}
}
// From right to left
for(size_t i = 0; i < HEIGHT; ++i){
int highest_tree = -1;
for(size_t j = WIDTH; j > 0; --j){
if(tree_height_map[i][j-1] > highest_tree){
highest_tree = tree_height_map[i][j-1];
if(!spotted_trees[i][j-1]){
result++;
spotted_trees[i][j-1] = true;
}
}
}
}
// From top to bottom
for(size_t j = 0; j < WIDTH; ++j){
int highest_tree = -1;
for(size_t i = 0; i < HEIGHT; ++i){
if(tree_height_map[i][j] > highest_tree){
highest_tree = tree_height_map[i][j];
if(!spotted_trees[i][j]){
result++;
spotted_trees[i][j] = true;
}
}
}
}
// From bottom to top
for(size_t j = 0; j < WIDTH; ++j){
int highest_tree = -1;
for(size_t i = HEIGHT; i > 0; --i){
if(tree_height_map[i-1][j] > highest_tree){
highest_tree = tree_height_map[i-1][j];
if(!spotted_trees[i-1][j]){
result++;
spotted_trees[i-1][j] = true;
}
}
}
}
cout << "Number of spotted trees: " << result << endl;
return 0;
}