Solve 2024 day 4 part 1

2024/day-04/main.cpp

@@ -0,0 +1,62 @@
+#include <iostream>
+#include <vector>
+
+using namespace std;
+
+vector<string> readInput()
+{
+    vector<string> lines;
+    string line;
+    while (getline(cin, line)) {
+        lines.push_back(line);
+    }
+    return lines;
+}
+
+int main()
+{
+    int numberOfOccurences = 0;
+    const vector<string> matrix = readInput();
+
+    // Horizontal
+    for (size_t rowIndex = 0; rowIndex < matrix.size(); rowIndex++) {
+        for (size_t colIndex = 0; colIndex < matrix[0].size() - 3; colIndex++) {
+            const string nextWord = matrix[rowIndex].substr(colIndex, 4);
+            if (nextWord == "XMAS" || nextWord == "SAMX") {
+                numberOfOccurences++;
+            }
+        }
+    }
+
+    // Vertical
+    for (size_t colIndex = 0; colIndex < matrix[0].size(); colIndex++) {
+        for (size_t rowIndex = 0; rowIndex < matrix.size() - 3; rowIndex++) {
+            string nextWord;
+            for (size_t i = 0; i <= 3; i++) {
+                nextWord += matrix[rowIndex + i][colIndex];
+            }
+            if (nextWord == "XMAS" || nextWord == "SAMX") {
+                numberOfOccurences++;
+            }
+        }
+    }
+
+    // Diagonal
+    for (size_t rowIndex = 0; rowIndex < matrix.size() - 3; rowIndex++) {
+        for (size_t colIndex = 0; colIndex < matrix[0].size() - 3; colIndex++) {
+            string nextWord1, nextWord2;
+            for (size_t i = 0, j = 3; i <= 3; i++, j--) {
+                nextWord1 += matrix[rowIndex + i][colIndex + i];
+                nextWord2 += matrix[rowIndex + j][colIndex + i];
+            }
+            if (nextWord1 == "XMAS" || nextWord1 == "SAMX") {
+                numberOfOccurences++;
+            }
+            if (nextWord2 == "XMAS" || nextWord2 == "SAMX") {
+                numberOfOccurences++;
+            }
+        }
+    }
+
+    cout << "Number of XMAS occurences: " << numberOfOccurences << endl;
+}