improve ex01

day03/main.cpp

@@ -7,12 +7,27 @@
 
 using namespace std;
 
-array<pair<int, int>, 8> directions = {{{-1, 0}, {1, 0}, {0, -1}, {0, 1}, {-1, -1}, {-1, 1}, {1, -1}, {1, 1}}};
-
 inline bool isSymbol(char c) {
     return (!isdigit(c) && c != '.');
 }
 
+enum Type { empty, symbol, number };
+using Element = pair<Type, int>;
+using Row = vector<Element>;
+using Map = vector<Row>;
+
+template <typename T>
+bool checkSurrounding(T &map, int i, int j, function<bool(Element)> check) {
+    static const array<pair<int, int>, 8> directions = {{{-1, 0}, {1, 0}, {0, -1}, {0, 1}, {-1, -1}, {-1, 1}, {1, -1}, {1, 1}}};
+    for (auto [id, jd] : directions) {
+        if (i + id < 0 || i + id >= map.size() || j + jd < 0 || j + jd >= map[i].size())
+            continue;
+        if (check(map[i + id][j + jd]))
+            return true;
+    }
+    return false;
+}
+
 int main(int argc, char **argv) {
     if (argc != 2) {
         cout << "Usage: " << argv[0] << " inputfile" << endl;
@@ -27,43 +42,38 @@ int main(int argc, char **argv) {
     }
 
     string line;
-    vector<vector<char>> map;
+    Map map;
     while (getline(inputFile, line)) {
-        vector<char> row;
-        for (auto &c : line) {
-            row.push_back(c);
+        Row row;
+        for (size_t i = 0; i < line.size(); ++i) {
+            if (isdigit(line[i])) {
+                int number = stoi(line.substr(i));
+                for (; isdigit(line[i]); ++i)
+                    row.push_back({Type::number, number});
+                --i;
+            } else if (isSymbol(line[i]))
+                row.push_back({Type::symbol, line[i]});
+            else
+                row.push_back({Type::empty, 0});
         }
         map.push_back(row);
     }
+
     int total = 0;
     for (size_t i = 0; i < map.size(); ++i) {
-        stringstream ss;
-        bool symbol = false;
-        for (size_t j = 0; j < map[i].size() + 1; ++j) {
-            if (j < map[i].size() && isdigit(map[i][j])) {
-                ss << map[i][j];
-                for (auto [id, jd] : directions) {
-                    if (i + id < 0 || i + id >= map.size() || j + jd < 0 || j + jd >= map[i].size())
-                        continue;
-                    if (isSymbol(map[i + id][j + jd]))
-                        symbol = true;
-                }
-            } else {
-                if (ss.str().empty())
-                    continue;
-                int value;
-                ss >> value;
-                ss = stringstream();
-                cout << value;
-                if (symbol) {
-                    total += value;
-                    symbol = false;
-                    cout << "X";
-                }
-                cout << " ";
+        bool hasSymbol = false;
+        int number = 0;
+        for (size_t j = 0; j < map[i].size(); ++j) {
+            if (map[i][j].first == Type::number) {
+                number = map[i][j].second;
+                if (checkSurrounding(map, i, j, [](Element e) { return (e.first == Type::symbol); }))
+                    hasSymbol = true;
+            }
+            if ((j == map.size() - 1 || map[i][j].first != Type::number) && hasSymbol) {
+                total += number;
+                hasSymbol = false;
             }
         }
-        cout << endl;
     }
     cout << "Total: " << total << endl;
 }