All tasks are done!

2025.03.14/08Ex/a.txt

@@ -0,0 +1,3 @@
+1 2 3 4
+1 1 1 1
+2 2 2 2

2025.03.14/08Ex/array_io.c

@@ -0,0 +1,40 @@
+#include <stdio.h>
+#include "array_io.h"
+
+io_status read_matrix(double *a, int n, int m, const char *name)
+{
+	int i, j;
+	FILE *fp;
+	if (!(fp = fopen(name, "r"))) return ERROR_OPEN;
+	for (i = 0; i < n; i++)
+		for (j = 0; j < m; j++)
+			if (fscanf(fp, "%lf", a + i * m + j) != 1) 
+				{fclose(fp); return ERROR_READ;}
+	fclose(fp);
+	return SUCCESS;
+}
+
+void print_matrix(const double *a, int n, int m, int p)
+{
+	int np = (n > p ? p : n);
+	int mp = (m > p ? p : m);
+	int i, j;
+
+	for (i = 0; i < np; i++)
+	{
+		for (j = 0; j < mp; j++)
+			printf(" %10.3e", a[i * m + j]);
+		printf("\n");
+	}
+}
+
+void init_matrix(double *a, int n, int m, int k)
+{
+	double (*q)(int, int, int, int);
+	double (*f[])(int, int, int, int) = {f1, f2, f3, f4};
+	int i, j;
+	q = f[k-1];
+	for (i = 0; i < n; i++)
+		for (j = 0; j < m; j++)
+			a[i * m + j] = q(n, m, i+1, j+1);
+}

2025.03.14/08Ex/array_io.h

@@ -0,0 +1,11 @@
+#ifndef ARRAY_IO_H
+#define ARRAY_IO_H
+
+#include "io_status.h"
+#include "init_f.h"
+
+io_status read_matrix(double *a, int n, int m, const char *name);
+void print_matrix(const double *a, int n, int m, int p);
+void init_matrix(double *a, int n, int m, int k);
+
+#endif

2025.03.14/08Ex/init_f.c

@@ -0,0 +1,30 @@
+#include "init_f.h"
+#include <stdlib.h>
+
+#define MAX(n, m) (n < m ? m : n)
+
+double f1(int n, int m, int i, int j)
+{
+	return MAX(n, m) - MAX(i, j) + 1;
+}
+
+double f2(int n, int m, int i, int j)
+{
+	(void)n;
+	(void)m;
+	return MAX(i, j);
+}
+
+double f3(int n, int m, int i, int j)
+{
+	(void)n;
+	(void)m;
+	return abs(i - j);
+}
+
+double f4(int n, int m, int i, int j)
+{
+	(void)n;
+	(void)m;
+	return 1./(i+j-1);
+}

2025.03.14/08Ex/init_f.h

@@ -0,0 +1,9 @@
+#ifndef INIT_F_H
+#define INIT_F_H
+
+double f1(int n, int m, int i, int j);
+double f2(int n, int m, int i, int j);
+double f3(int n, int m, int i, int j);
+double f4(int n, int m, int i, int j);
+
+#endif

2025.03.14/08Ex/io_status.h

@@ -0,0 +1,13 @@
+#ifndef IO_STATUS_H
+#define IO_STATUS_H
+
+#define LEN 1234
+
+typedef enum _io_status
+{
+	SUCCESS,
+	ERROR_OPEN,
+	ERROR_READ
+} io_status;
+
+#endif

2025.03.14/08Ex/main.c

@@ -0,0 +1,67 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+#include "array_io.h"
+#include "io_status.h"
+#include "solve.h"
+
+/* ./a.out n m p k [filename] */
+int main(int argc, char *argv[])
+{
+	double t, res, *a;
+	int n, m, p, k, task = 8;
+	char *name = 0;
+	
+	if (!((argc == 5 || argc == 6) && 
+				sscanf(argv[1], "%d", &n) == 1 && 
+				sscanf(argv[2], "%d", &m) == 1 && 
+				sscanf(argv[3], "%d", &p) == 1 &&
+				sscanf(argv[4], "%d", &k) == 1 &&
+				k >= 0 && k <= 4 && (!(k == 0 && argc != 6))))
+	{
+		printf("Usage: %s n m p k [filename]\n", argv[0]);
+		return 1;
+	}
+	if (argc == 6) name = argv[5];
+	
+	a = (double *)malloc(n * m * sizeof(double));
+	if (!a)
+	{
+		printf("Not enough memory\n");
+		return 2;
+	}
+
+	if (name)
+	{ /* из файла */
+		io_status ret;
+		ret = read_matrix(a, n, m, name);
+		do {
+			switch (ret)
+			{
+				case SUCCESS:
+					continue;
+				case ERROR_OPEN:
+					printf("Cannot open %s\n", name);
+					break;
+				case ERROR_READ:
+					printf("Cannot read %s\n", name);
+			}
+			free(a);
+			return 3;
+		} while (0);
+	} else init_matrix(a, n, m, k);
+
+	printf("Matrix:\n");
+	print_matrix(a, n, m, p);
+
+	t = clock();
+	res = t8_solve(a, n, m);
+	t = (clock() - t) / CLOCKS_PER_SEC;
+
+	printf("New matrix:\n");
+	print_matrix(a, n, m, p);
+	printf ("%s : Task = %d Result = %e Elapsed = %.2f\n", argv[0], task, res, t);
+	
+	free(a);
+	return 0;
+}

2025.03.14/08Ex/solve.c

@@ -0,0 +1,32 @@
+#include "solve.h"
+#include <math.h>
+
+#define eps 1e-9
+
+int compare(const double a, const double b)
+{
+	if (a - b > eps) return 1;
+	else if (b - a > eps) return -1;
+	return 0;
+}
+
+double t8_solve(double *a, int n, int m)
+{
+	int i, j;
+	double cur = 0, maximum = 0;
+	for (i = 0; i < n; i++)
+		for (j = 0; j < m; j++)
+			if (i == 0 || i == n-1 || j == 0 || j == m-1)
+				if (compare(fabs(a[i*m + j]), maximum) == 1)
+					maximum = fabs(a[i*m + j]);
+	
+	for (i = n-2; i > 0; i--)
+		for (j = m-2; j > 0; j--)
+		{
+			cur = (a[(i+1)*m + j] + a[(i-1)*m + j] + a[i*m + (j-1)] + a[i*m + (j+1)]) / 5;
+			if (compare(fabs(cur), maximum) == 1) maximum = fabs(cur);
+			a[i*m + j] = cur;
+		}
+
+	return maximum;
+}

2025.03.14/08Ex/solve.h

@@ -0,0 +1,7 @@
+#ifndef SOLVE_H
+#define SOLVE_H
+
+int compare(const double a, const double b);
+double t8_solve(double *a, int n, int m);
+
+#endif