Finished StringCheck Method but did not test yet

imageInput.c

@@ -8,6 +8,27 @@
 
 // TODO Implementieren Sie geeignete Hilfsfunktionen für das Lesen der Bildserie aus einer Datei
 
+int checkString (FILE *file){ //Checks if String at the start of File equals expected Format (0 for wrong 1 for right)
+	if (file == NULL){ //returns 0 for empty file
+		return 0;
+		}
+	char expectedString[] = FILE_HEADER_STRING;
+	char actualString[BUFFER_SIZE];
+
+	rewind(file);
+	size_t bytesRead = fread(actualString, 1,27 , file); //Stores Bytes of start of File to actualString
+	if (bytesRead != 27){
+	return 0;} //Returns 0 if File is to short
+	actualString[27] = '\0';
+
+	if (strcmp(actualString, expectedString) != 0){
+	return 0;
+}
+	else{
+	return 1;
+}
+}
+
 // TODO Vervollständigen Sie die Funktion readImages unter Benutzung Ihrer Hilfsfunktionen
 GrayScaleImageSeries *readImages(const char *path)
 {

matrix.c

@@ -28,17 +28,47 @@ void clearMatrix(Matrix *matrix)
 
 void setMatrixAt(MatrixType value, Matrix matrix, unsigned int rowIdx, unsigned int colIdx)
 {
-    
+    if (rowIdx >= matrix.rows || colIdx >= matrix.cols){
+        printf("Index out of bounds\n"); //Error Message because Index Input exceeds Matrix
+}
+    else{
+        matrix.buffer[rowIdx * matrix.cols + colIdx] = value; //Writes Value of value variable in the selected place in Matrix
+}
 }
 
 MatrixType getMatrixAt(const Matrix matrix, unsigned int rowIdx, unsigned int colIdx)
 {
+    if (rowIdx >= matrix.rows || colIdx >= matrix.cols){
+       printf("Index out of bounds\n");
+       return 0;
+    }
+    else{
 
+       MatrixType value = matrix.buffer[rowIdx * matrix.cols + colIdx]; //Stores value of selected place of Matrix in value variable
+        return value;
 }
+  }
 
 Matrix add(const Matrix matrix1, const Matrix matrix2)
 {
+    Matrix MatrixErgebnis = createMatrix(matrix1.rows, matrix1.cols); //Creating Result Matrix
+    if(matrix1.cols != matrix2.cols || matrix1.rows != matrix2.rows){
+        printf("Matrix dimensions do not match\n"); //Error Message if dimensions of Input Matrixes are not identical
+        MatrixErgebnis = clearMatrix(MatrixErgebnis);
+        return MatrixErgebnis;
+    }
+    else{
 
+        for (unsigned int i = 0; i < matrix1.rows; i++){
+            for (unsigned int j = 0; j < matrix1.cols; j++){
+                //Adding Matrix Elements of same row and col index together and store in new Matrix
+                MatrixErgebnis.buffer[i * matrix1.cols + j] = matrix1.buffer[i * matrix1.cols + j] + matrix2.buffer[i * matrix1.cols + j];
+
+                }
+        }
+
+  }
+return MatrixErgebnis;
 }
 
 Matrix multiply(const Matrix matrix1, const Matrix matrix2)