.

bac2/os/chap2/ex4.c

@@ -0,0 +1,61 @@
+#include <inttypes.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#define AT(mat, x, y) ((mat)->data[((x)-1) + ( ((y)-1) * ((mat)->w) )])
+
+#define PRINT_MAT(mat) for (int i = 1; i <= (mat)->h; ++i) { for (int j = 1; j <= (mat)->w; ++j) { printf("%d,", AT((mat),(j), (i))); } printf("\n"); } printf("\n");
+
+typedef struct {
+	uint8_t w, h;
+	int *data;
+} MAT;
+
+MAT *new(uint8_t, uint8_t);
+MAT *mul(MAT*, MAT*);
+
+int main(void)
+{
+	MAT* a = new(3, 2);
+	MAT* b = new(3, 3);
+	MAT* mult;
+
+
+	AT(a, 1, 1) = 0; AT(a, 2, 1) = 1; AT(a, 3, 1) = 2;
+	AT(a, 1, 2) = 3; AT(a, 2, 2) = 4; AT(a, 3, 2) = 5;
+	/* AT(a, 1, 3) = 6; AT(a, 2, 3) = 7; AT(a, 3, 3) = 8; */
+	PRINT_MAT(a);
+
+	AT(b, 1, 1) = 1; AT(b, 2, 1) = 0; AT(b, 3, 1) = 0;
+	AT(b, 1, 2) = 0; AT(b, 2, 2) = 1; AT(b, 3, 2) = 0;
+	AT(b, 1, 3) = 0; AT(b, 2, 3) = 0; AT(b, 3, 3) = 1;
+	PRINT_MAT(b);
+
+	mult = mul(a,b);
+	PRINT_MAT(mult);
+	
+}
+
+MAT *new(uint8_t w, uint8_t h){
+	MAT* ret = malloc(sizeof(MAT));
+	ret->w = w; 
+	ret->h = h; 
+	ret->data = malloc(sizeof(int) * w * h);
+	return ret;
+}
+
+MAT *mul(MAT *a, MAT *b){
+	if(a->w != b->h)
+		return NULL;
+	MAT* ret = new(b->w, a->h);
+	for (int i = 1; i <= a->h; ++i) {
+		for (int j = 1; j <= b->w; ++j) {
+			int tmp = 0;
+			for (int k = 1; k <= a->w; ++k) {
+				tmp += AT(a, k, i) * AT(b, j, k);
+			}
+			AT(ret, j, i) = tmp;
+		}
+	}
+	return ret;
+}