хуятрица

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

#define MAX_SIZE 100

typedef double (*Matrix)[MAX_SIZE];

double norm(Matrix A, int n);
double determinant(Matrix A, int n);
double** inverse_matrix(Matrix A, int n);

double norm(Matrix A, int n) {
    double max_norm = 0.0;
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            double abs_val = fabs(A[i][j]);
            if (abs_val > max_norm) {
                max_norm = abs_val;
            }
        }
    }
    return max_norm;
}

double** inverse_matrix(Matrix A, int n) {
    double** adjoint = malloc(n * sizeof(double*));
    for (int i = 0; i < n; i++) {
        adjoint[i] = malloc(n * sizeof(double));
    }
    // Вычисление алгебраических дополнений
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            int sub_n = n - 1;
            double (*sub_matrix)[sub_n] = malloc(sub_n * sizeof(double));
            for (int k = 0; k < sub_n; k++) {
                for (int l = 0; l < sub_n; l++) {
                    sub_matrix[k][l] = A[k < i ? k : k + 1][l < j ? l : l + 1];
                }
            }

            double det_sub = determinant(sub_matrix, sub_n);
            int sign = (i + j) % 2 == 0 ? 1 : -1;
            adjoint[i][j] = sign * det_sub;

            free(sub_matrix);
        }
    }

    // Транспонирование матрицы алгебраических дополнений
    double** A_inv = malloc(n * sizeof(double*));
    for (int i = 0; i < n; i++) {
        A_inv[i] = malloc(n * sizeof(double));
    }

    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            A_inv[i][j] = adjoint[j][i];
        }
    }

    for (int i = 0; i < n; i++) {
        free(adjoint[i]);
    }
    free(adjoint);

    return A_inv;
}

double determinant(Matrix A, int n) {
    double det = 0.0;
    if (n == 1) {
        det = A[0][0];
    } else if (n == 2) {
        det = A[0][0] * A[1][1] - A[0][1] * A[1][0];
    } else {
        for (int j = 0; j < n; j++) {
            double (*sub_matrix)[n - 1] = malloc((n - 1) * sizeof(double));
            for (int k = 1; k < n; k++) {
                for (int l = 0; l < n; l++) {
                    sub_matrix[k - 1][l < j ? l : l + 1] = A[k][l];
                }
            }

            det += (A[0][j] * (j % 2 == 0 ? 1 : -1) * determinant(sub_matrix, n - 1));
            free(sub_matrix);
        }
    }
    return det;
}

int main() {
    int n;
    FILE *file = fopen("input.txt", "r");
    if (file == NULL) {
        printf("Error opening file.\n");
        return -1;
    }

    fscanf(file, "%d", &n);
    double (*A)[n] = malloc(n * sizeof(double));
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            fscanf(file, "%lf", &A[i][j]);
        }
    }
    fclose(file);

    double** A_inv = inverse_matrix(A, n);
    double norm_n = norm((Matrix) A_inv, n);
    printf("Норма невязки: %.2e\n", norm_n);

    for (int i = 0; i < n; i++) {
        free(A[i]);
    }
    free(A);

    for (int i = 0; i < n; i++) {
        free(A_inv[i]);
    }
    free(A_inv);

    return 0;
}