added todays assigment

20221216/main.c

+#include <stdio.h>
+
+#define ROWS(a) (sizeof(a) / sizeof(a[0]))
+#define COLS(a) (sizeof(a[0]) / sizeof(a[0][0]))
+
+void input(int rows, int cols, int matrix[][cols]) {
+    for (int i = 0; i < rows; ++i) {
+        for (int j = 0; j < cols; ++j) {
+            printf("[%d][%d]: ", i, j);
+            scanf("%d", &matrix[i][j]);
+        }
+    }
+}
+
+int count_eq(int rows, int cols, int matrix[][cols], int key) {
+    int ret = 0;
+    for (int i = 0; i < rows; ++i) {
+        for (int j = 0; j < cols; ++j) {
+            if (matrix[i][j] == key) {
+                ++ret;
+            }
+        }
+    }
+    return ret;
+}
+
+int sum(
+        int rows1, int cols1, int a1[][cols1],
+        int rows2, int cols2, int a2[][cols2],
+        int rows3, int cols3, int a3[][cols3]) 
+{
+    int ret;
+    if (rows1 == rows2 && rows2 == rows3 && cols1 == cols2 && cols2 == cols3) {
+        int rows = rows1;
+        int cols = cols1;
+
+        for (int i = 0; i < rows; ++i) {
+            for (int j = 0; j < cols; ++j) {
+                a3[i][j] = a1[i][j] + a2[i][j];
+            }
+        }
+
+        ret = 0;
+    } else {
+        ret = -1;
+    }
+    return ret;
+}
+
+void print(int rows, int cols, int matrix[][cols]) {
+    for (int i = 0; i < rows; ++i) {
+        for (int j = 0; j < cols; ++j) {
+            printf("%3d ", matrix[i][j]);
+        }
+        puts("");
+    }
+}
+
+
+int multiply(
+        int rows1, int cols1, int a1[][cols1],
+        int rows2, int cols2, int a2[][cols2],
+        int rows3, int cols3, int a3[][cols3]) 
+{
+    int ret;
+    if (cols1 == rows2 && rows1 == rows3 && cols2 == cols3) {
+        for (int i = 0; i < rows1; ++i) {
+            for (int j = 0; j < cols2; ++j) {
+
+                int sum = 0;
+                for (int k = 0; k < rows2; ++k) {
+                    sum += a1[i][k] * a2[k][j];
+                }
+                a3[i][j] = sum;
+
+            }
+        }
+
+        ret = 1;
+    } else {
+        ret = -1;
+    }
+
+    return ret;
+}
+
+int main(void) {
+    int a1[2][3];
+    int a2[3][2];
+
+    puts("inserimento A");
+    input(ROWS(a1), COLS(a1), a1);
+    puts("inserimento B");
+    input(ROWS(a2), COLS(a2), a2);
+
+    int x;
+    printf("inserire x: ");
+    scanf("%d", &x);
+    printf("instanze di %d in A: %d\n", x, count_eq(ROWS(a1), COLS(a1), a1, x));
+
+    int y;
+    printf("inserire y: ");
+    scanf("%d", &y);
+    printf("instanze di %d in B: %d\n", y, count_eq(ROWS(a2), COLS(a2), a2, y));
+
+    int s[ROWS(a1)][COLS(a1)];
+    if (sum(ROWS(a1), COLS(a1), a1, ROWS(a2), COLS(a2), a2, ROWS(s), COLS(s), s) < 0) {
+        fputs("somma impossibile\n", stderr);
+    } else {
+        print(ROWS(s), COLS(s), s);
+    }
+
+    int m[2][2];
+    if (multiply(ROWS(a1), COLS(a1), a1, ROWS(a2), COLS(a2), a2, ROWS(m), COLS(m), m) < 0) {
+        fputs("prodotto impossibile\n", stderr);
+    } else {
+        print(ROWS(m), COLS(m), m);
+    }
+}