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Solve 2024 day 4 part 2

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SebastianStork 2024-12-13 16:35:30 +01:00
parent 943db1881c
commit 713541b469
1 changed files with 38 additions and 0 deletions
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38
2024/day-04/main.cpp
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@ -18,6 +18,11 @@ bool wordIsXmas(const string &word)
return word == "XMAS" || word == "SAMX"; return word == "XMAS" || word == "SAMX";
} }
bool wordIsMas(const string &word)
{
return word == "MAS" || word == "SAM";
}
int xmasCountAt(const vector<string> &matrix, const size_t rowIndex, const size_t colIndex) int xmasCountAt(const vector<string> &matrix, const size_t rowIndex, const size_t colIndex)
{ {
const size_t numberOfRows = matrix.size(); const size_t numberOfRows = matrix.size();
@ -61,6 +66,34 @@ int xmasCountAt(const vector<string> &matrix, const size_t rowIndex, const size_
return xmasCount; return xmasCount;
} }
bool crossMasExistsAt(const vector<string> &matrix, const size_t rowIndex, const size_t colIndex)
{
const size_t numberOfRows = matrix.size();
const size_t numberOfCols = matrix[0].size();
if (rowIndex + 2 >= numberOfRows || colIndex + 2 >= numberOfCols) {
return false;
}
string downDiagonalWord;
for (size_t i = 0; i <= 2; i++) {
downDiagonalWord += matrix[rowIndex + i][colIndex + i];
}
if (!wordIsMas(downDiagonalWord)) {
return false;
}
string upDiagonalWord;
for (size_t i = 0; i <= 2; i++) {
upDiagonalWord += matrix[rowIndex + (2 - i)][colIndex + i];
}
if (!wordIsMas(upDiagonalWord)) {
return false;
}
return true;
}
int main() int main()
{ {
const vector<string> matrix = readInput(); const vector<string> matrix = readInput();
@ -68,13 +101,18 @@ int main()
const size_t numberOfCols = matrix[0].size(); const size_t numberOfCols = matrix[0].size();
int numberOfXmasOccurrences = 0; int numberOfXmasOccurrences = 0;
int numberOfCrossMasOccurrences = 0;
for (size_t rowIndex = 0; rowIndex < numberOfRows; rowIndex++) { for (size_t rowIndex = 0; rowIndex < numberOfRows; rowIndex++) {
for (size_t colIndex = 0; colIndex < numberOfCols; colIndex++) { for (size_t colIndex = 0; colIndex < numberOfCols; colIndex++) {
numberOfXmasOccurrences += xmasCountAt(matrix, rowIndex, colIndex); numberOfXmasOccurrences += xmasCountAt(matrix, rowIndex, colIndex);
numberOfCrossMasOccurrences += crossMasExistsAt(matrix, rowIndex, colIndex);
} }
} }
// Part one // Part one
cout << "Number of XMAS occurrences: " << numberOfXmasOccurrences << endl; cout << "Number of XMAS occurrences: " << numberOfXmasOccurrences << endl;
// Part two
cout << "Number of X-MAS occurrences: " << numberOfCrossMasOccurrences << endl;
} }