#include <stdio.h>

#define NUM_OF_EQUATIONS 3
#define NUM_OF_TERMS 6

double equationOneVars[] = { 5, 2, 1, 0, 0, 20 };
double equationTwoVars[] = { 5, 8, 0, 1, 0, 50 };
double equationThreeVars[] = { -1, 2, 0, 0, 1, 0 };

double terms[NUM_OF_TERMS * NUM_OF_EQUATIONS];
double difTerms[(NUM_OF_TERMS - 1) * NUM_OF_EQUATIONS];

double matrix[NUM_OF_EQUATIONS][NUM_OF_TERMS];

void printMatrix(char* a, char* b, char* c, char* d, char* e) {
    printf("\n%s %s %s %s %s\n", a, b, c, d, e);
    for (int i = 0; i < NUM_OF_EQUATIONS; i++) {
        for (int j = 0; j < NUM_OF_TERMS; j++) {
            printf("%f ", matrix[i][j]);
        }
        printf("\n");
    }
    printf("\n");
}

void makeOtherMatrix() {
    double oldMatrix[NUM_OF_EQUATIONS][NUM_OF_TERMS];
    int k = 0;

    for (int i = 0; i < NUM_OF_EQUATIONS; i++) {
        for (int j = 0; j < NUM_OF_TERMS; j++) {
            oldMatrix[i][j] = terms[k];
            k++;
        }
    }

    double difMatrix[NUM_OF_EQUATIONS][NUM_OF_TERMS - 1];
    k = 0;

    for (int i = 0; i < NUM_OF_EQUATIONS; i++) {
        for (int j = 0; j < NUM_OF_TERMS - 1; j++) {
            difMatrix[i][j] = difTerms[k];
            k++;
        }
    }
}

void findNegative(int* negativeCol, double* negativeNum) {
    *negativeNum = 0;
    *negativeCol = 0;
    for (int i = 0; i < NUM_OF_TERMS; i++) {
        if (matrix[NUM_OF_EQUATIONS - 1][i] < *negativeNum) {
            *negativeNum = matrix[NUM_OF_EQUATIONS - 1][i];
            *negativeCol = i;
        }
    }
}

int findSmallQuotient(int col) {
    int smallestRow = 0;
    double smallestNum = __DBL_MAX__;
    for (int i = 0; i < NUM_OF_EQUATIONS; i++) {
        if (matrix[i][NUM_OF_TERMS - 1] != 0 && matrix[i][col] != 0 && i != (NUM_OF_EQUATIONS - 1) && (matrix[i][NUM_OF_TERMS - 1] / matrix[i][col]) < smallestNum) {
            smallestNum = (matrix[i][NUM_OF_TERMS - 1] / matrix[i][col]);
            smallestRow = i;
        }
    }
    return smallestRow;
}

void start() {
    int col;
    double negativeNum;
    findNegative(&col, &negativeNum);
    while (negativeNum < 0) {
        int row = findSmallQuotient(col);
        multiplyRow(row, (1 / matrix[row][col]));
        (void)printf("%d %d %f get_ready\n", row, col, (1 / matrix[row][col]));
        findNegative(&col, &negativeNum);

        for (int i = 0; i < NUM_OF_EQUATIONS; i++) {
            if (i != row) {
                makeTermsZero(i, col, row);
                (void)printf("%d %d %d get_Freddy\n", i, col, row);
            }
        }
        findNegative(&col, &negativeNum);
    }
}

void makeTermsZero(int row, int col, int rowTwo) {
    addMultiplyRows(row, rowTwo, -1 * matrix[row][col]);
}

void switchRows(int rowNum, int rowNumTwo) {
    double subRow[NUM_OF_TERMS];
    for (int i = 0; i < NUM_OF_TERMS; i++) {
        subRow[i] = matrix[rowNumTwo][i];
    }
    for (int i = 0; i < NUM_OF_TERMS; i++) {
        matrix[rowNumTwo][i] = matrix[rowNum][i];
    }
    for (int i = 0; i < NUM_OF_TERMS; i++) {
        matrix[rowNum][i] = subRow[i];
    }
}

void multiplyRow(int rowNum, double mult) {
    for (int i = 0; i < NUM_OF_TERMS; i++) {
        matrix[rowNum][i] = mult * matrix[rowNum][i];
    }
}

void addMultiplyRows(int rowNum, int rowNumTwo, double mult) {
    for (int i = 0; i < NUM_OF_TERMS; i++) {
        matrix[rowNum][i] = matrix[rowNum][i] + (mult * matrix[rowNumTwo][i]);
    }
}

int main() {
    for (int i = 0; i < NUM_OF_TERMS; i++) {
        terms[i] = equationOneVars[i];
        terms[NUM_OF_TERMS + i] = equationTwoVars[i];
        terms[2 * NUM_OF_TERMS + i] = equationThreeVars[i];
    }

    int j = 0;
    for (int i = 0; i < NUM_OF_EQUATIONS; i++) {
        if (i % NUM_OF_TERMS != 0) {
            difTerms[j] = terms[i];
            j++;
        }
    }

    int k = 0;
    for (int i = 0; i < NUM_OF_EQUATIONS; i++) {
        for (int j = 0; j < NUM_OF_TERMS; j++) {
            matrix[i][j] = terms[k];
            k++;
        }
    }

    printMatrix("", "", "", "", "");

    start();

    printMatrix("", "", "", "", "");

    return 0;
}