Added matrix calculator

1 files changed, 349 insertions, 0 deletions

diff --git a/C/MatrixCalculator.c b/C/MatrixCalculator.c
new file mode 100644
index 0000000..ecd9370
--- /dev/null
+++ b/C/MatrixCalculator.c
@@ -0,0 +1,349 @@
+/* 
+ * SCROLL TO BOTTOM FOR DOCUMENTATION 
+ */
+
+#include <stdio.h>  // printf, scanf
+#include <string.h> // strcspn, strtok
+#include <stdlib.h> // atoi, atof
+
+#define MAX_LINE_WIDTH 1024
+#define MATRIX_NUMBER_DELIMITER " "
+
+#define CMND_END          "end"
+#define CMND_PRINT_MATRIX "print"
+#define CMND_PRINT_VARS   "printv"
+#define CMND_SWAP_ROWS    "swap"
+#define CMND_MULT_ROW     "mult"
+#define CMND_DIV_ROW      "div"
+#define CMND_SUM_ROW      "sum"
+
+/* Matrix commands */
+void sumRows(char *command, int matrixRows, int matrixCols, double matrix[][matrixCols], int swapVars, double vars[][matrixCols]);
+void multRows(char *command, int matrixRows, int matrixCols, double matrix[][matrixCols], int swapVars, double vars[][matrixCols]);
+void divRows(char *command, int matrixRows, int matrixCols, double matrix[][matrixCols], int swapVars, double vars[][matrixCols]);
+void swapRows(char *command, int matrixRows, int matrixCols, double matrix[][matrixCols], int swapVars, double vars[][matrixCols]);
+
+/* Arrays */
+void assignArrValues(int cols, double arrDest[], double arrSrc[]);
+void multArrValues(int len, double arr[], double value);
+
+/* IO */
+void printMatrix(int mr, int mc, double matrix[][mc]);
+void inputToMatrix(char inputBuffer[], int matrixRows, int matrixCols, double matrix[][matrixCols]);
+void getInput(char inputBuffer[MAX_LINE_WIDTH]);
+
+
+int main() {
+	/* 
+	 * Get matricies
+	 */
+
+	int rows, cols, hasVars;
+	scanf("%d %d %d\n", &rows, &cols, &hasVars);
+
+	double matrix[rows][cols];
+	double vars[rows][cols];
+
+	char inputBuffer[MAX_LINE_WIDTH];
+
+	inputToMatrix(inputBuffer, rows, cols, matrix);
+
+	if (hasVars)
+		inputToMatrix(inputBuffer, rows, cols, vars);
+
+	/* 
+	 * Modify matricies
+	 */
+
+	printf("Commands:\n");
+
+	char *command;
+	do {
+		getInput(inputBuffer);
+		command = strtok(inputBuffer, MATRIX_NUMBER_DELIMITER);
+
+		if (!strcmp(inputBuffer, CMND_SWAP_ROWS))
+			swapRows(command, rows, cols, matrix, hasVars, vars);
+
+		else if (!strcmp(inputBuffer, CMND_MULT_ROW))
+			multRows(command, rows, cols, matrix, hasVars, vars);
+
+		else if (!strcmp(inputBuffer, CMND_DIV_ROW))
+			divRows(command, rows, cols, matrix, hasVars, vars);
+
+		else if (!strcmp(inputBuffer, CMND_SUM_ROW))
+			sumRows(command, rows, cols, matrix, hasVars, vars);
+
+		else if (!strcmp(inputBuffer, CMND_PRINT_MATRIX))
+			printMatrix(rows, cols, matrix);
+
+		else if (!strcmp(inputBuffer, CMND_PRINT_VARS))
+			printMatrix(rows, cols, vars);
+
+	} while (strcmp(inputBuffer, CMND_END) != 0);
+
+	/* 
+	 * End print
+	 */
+
+	printMatrix(rows, cols, matrix);
+	if (hasVars)
+		printMatrix(rows, cols, vars);
+}
+
+/* 
+ * Matrix commands
+ */
+
+void sumRows(char *command, int matrixRows, int matrixCols, double matrix[][matrixCols], int sumVars, double vars[][matrixCols]) {
+	/* Get input */
+
+	command = strtok(NULL, MATRIX_NUMBER_DELIMITER);
+	int rowSrc = atoi(command) - 1;
+
+	command = strtok(NULL, MATRIX_NUMBER_DELIMITER);
+	int rowDst = atoi(command) - 1;
+
+	command = strtok(NULL, MATRIX_NUMBER_DELIMITER);
+	double mult = atof(command);
+
+	double tmp[matrixCols];
+
+	/* Sum matrix rows */
+
+	assignArrValues(matrixCols, tmp, matrix[rowSrc]);
+	multArrValues(matrixCols, tmp, mult);
+
+	for (int i = 0; i < matrixCols; i++)
+		matrix[rowDst][i] += tmp[i];
+
+	/* Sum var rows */
+
+	if (sumVars) {
+		assignArrValues(matrixCols, tmp, vars[rowSrc]);
+		multArrValues(matrixCols, tmp, mult);
+
+		for (int i = 0; i < matrixCols; i++)
+			vars[rowDst][i] += tmp[i];
+	}
+}
+
+void multRows(char *command, int matrixRows, int matrixCols, double matrix[][matrixCols], int multVars, double vars[][matrixCols]) {
+	/* Get input */
+
+	command = strtok(NULL, MATRIX_NUMBER_DELIMITER);
+	int row = atoi(command) - 1;
+
+	command = strtok(NULL, MATRIX_NUMBER_DELIMITER);
+	double amount = atof(command);
+
+	/* Multiply matrix row */
+
+	multArrValues(matrixCols, matrix[row], amount);
+
+	/* Multiply var row */
+
+	if (multVars)
+		multArrValues(matrixCols, vars[row], amount);
+}
+
+void divRows(char *command, int matrixRows, int matrixCols, double matrix[][matrixCols], int divVars, double vars[][matrixCols]) {
+	/* Get input */
+
+	command = strtok(NULL, MATRIX_NUMBER_DELIMITER);
+	int row = atoi(command) - 1;
+
+	command = strtok(NULL, MATRIX_NUMBER_DELIMITER);
+	double amount = atof(command);
+
+	/* Divide matrix row */
+
+	multArrValues(matrixCols, matrix[row], 1.0/amount);
+
+	/* Divide var row */
+
+	if (divVars)
+		multArrValues(matrixCols, vars[row], 1.0/amount);
+}
+
+void swapRows(char *command, int matrixRows, int matrixCols, double matrix[][matrixCols], int swapVars, double vars[][matrixCols]) {
+	/* Get input */
+
+	command = strtok(NULL, MATRIX_NUMBER_DELIMITER);
+	int row1 = atoi(command) - 1;
+
+	command = strtok(NULL, MATRIX_NUMBER_DELIMITER);
+	int row2 = atoi(command) - 1;
+
+	double tmp[matrixCols];
+
+	/* Swap matrix rows */
+
+	assignArrValues(matrixCols, tmp, matrix[row1]);
+	assignArrValues(matrixCols, matrix[row1], matrix[row2]);
+	assignArrValues(matrixCols, matrix[row2], tmp);
+
+	/* Swap var rows */
+
+	if (swapVars) {
+		assignArrValues(matrixCols, tmp, vars[row1]);
+		assignArrValues(matrixCols, vars[row1], vars[row2]);
+		assignArrValues(matrixCols, vars[row2], tmp);
+	}
+}
+
+/*
+ * Arrays
+ */
+
+void assignArrValues(int len, double arrDest[], double arrSrc[]) {
+	for (int i = 0; i < len; i++)
+		arrDest[i] = arrSrc[i];
+}
+
+void multArrValues(int len, double arr[], double value) {
+	for (int i = 0; i < len; i++)
+		arr[i] *= value;
+}
+
+/* 
+ * IO 
+ */
+
+void printMatrix(int mr, int mc, double matrix[][mc]) {
+	for (int r = 0; r < mr; r++) {
+		/* Left bracket */
+
+		if (r == 0) printf("/");
+		else if (r == mr - 1) printf("\\");
+		else printf("|");
+
+		/* Middle values */
+
+		for (int c = 0; c < mc; c++)
+			printf(" %.3g ", matrix[r][c]);
+
+		/* Right bracket */
+
+		if (r == 0) printf("\\");
+		else if (r == mr - 1) printf("/");
+		else printf("|");
+		printf("\n");
+	}
+}
+
+void inputToMatrix(char inputBuffer[], int matrixRows, int matrixCols, double matrix[][matrixCols]) {
+	char *singleVal;
+	for (int r = 0; r < matrixRows; r++) {
+		/* Get input */
+
+		getInput(inputBuffer);
+		singleVal = strtok(inputBuffer, MATRIX_NUMBER_DELIMITER);
+
+		/* Assign input to matrix */
+
+		for (int c = 0; c < matrixCols; c++) {
+			matrix[r][c] = atof(singleVal);
+
+			singleVal = strtok(NULL, MATRIX_NUMBER_DELIMITER);
+		}
+	}
+}
+
+void getInput(char inputBuffer[MAX_LINE_WIDTH]) {
+	fgets(inputBuffer, MAX_LINE_WIDTH, stdin);
+	inputBuffer[strcspn(inputBuffer, "\n")] = 0; // Removes trailing \n
+}
+
+/* This is a small "calculator" for matricies. You type in the values of your matricies, then what actions to do with the rows and finally you'll get your calculated result.
+ * If your matrix uses variables alongside numbers, you can use the "var" matrix, which will calculate the result for each variable separately
+ *
+ * All inputs must be separated by spaces!
+ * First input should be three numbers: amount of rows, amount of columns and whether to use the var matrix (0 for "don't use it", anything else for "use it").
+ * After that you type in the values of your matricies, each number separated by a space and each line separated by a newline.
+ *
+ * All rows are indexed from 1! So, if you have 3 rows, the first one is at "index" 1 (index when typing in command)
+ *
+ * Then you can do the commands. There are 7 different ones in total:
+ * - end : ends the app (and prints the matricies)
+ * - print : prints the normal matrix
+ * - printv : prints the var matrix
+ * - swap <srcRow> <destRow> : swaps the values between two rows
+ * - mult <row> <multiplier> : multiplies a row by a given number (and saves that to the row)
+ * - div <row> divisor : divides a row by a given number (and saves that to the row)
+ * - sum <srcRow> <destRow> <srcMultiplier> : multiplies a row by a given number (without modifying it) and adds it to another row (sample usage: multiply first row by 1 and sum that to the 3rd row: sum 1 2 1)
+
+ * Sample usage (what gets typed and what gets outputted):
+ * (Stuff that are typed in by the use start with ** in the examples)
+ *
+ * I. No vars
+ *
+ * Matrix in task looks like:
+ * /  1 -1 0 -1 \
+ * |  2 -4 2 10 |
+ * \ -1  1 1  5 /
+ *
+** 3 4 0
+** 1 -1 0 -1
+** 2 -4 2 10
+** -1 1 1 5
+ * Commands:
+** div 2 2
+** swap 1 2
+** sum 1 2 -1
+** print
+ * / 1  -2  1  5 \
+ * | 0  1  -1  -6 |
+ * \ -1  1  1  5 /
+** sum 1 3 1
+** sum 2 3 1
+** end
+ * / 1  -2  1  5 \
+ * | 0  1  -1  -6 |
+ * \ 0  0  1  4 /
+ *
+ * (I'm too lazy to implement a system for aligning the numbers properly)
+ *
+ * I. With vars
+ *
+ * Matrix in task looks like:
+ * /  1 -1   0   -1 \
+ * |  2 -4 2*p 10*q |
+ * \ -1  1   1    5 /
+ *
+** 3 4 1
+** 1 -1 0 -1
+** 2 -4 2 10
+** -1 1 1 5
+** 0 0 0 0
+** 0 0 1 1
+** 0 0 0 0
+ * Commands:
+** div 2 2
+** swap 1 2
+** sum 1 2 -1
+** print
+ * / 1  -2  1  5 \
+ * | 0  1  -1  -6 |
+ * \ -1  1  1  5 /
+** printv
+ * / 0  0  0.5  0.5 \
+ * | 0  0  -0.5  -0.5 |
+ * \ 0  0  0  0 /
+** sum 1 3 1
+** sum 2 3 1
+** end
+ * / 1  -2  1  5 \
+ * | 0  1  -1  -6 |
+ * \ 0  0  1  4 /
+ * / 0  0  0.5  0.5 \
+ * | 0  0  -0.5  -0.5 |
+ * \ 0  0  0  0 /
+ *
+ * You'll have to add the first value from normal matrix to the value of var matrix * variable
+ * So, the proper result looks something like:
+ * / 1  -2   1+0.5*p   5+0.5*q \
+ * | 0   1  -1-0.5*p  -6-0.5*q |
+ * \ 0   0         1         4 /
+ * (I'm too lazy to implement this type of printing) 
+ */