Changed algorithm of storing negatives

Author: studentfedorov

Lab5/src/main.c

@@ -19,18 +19,16 @@ unsigned char *loadtext(char *name, int *number){
 			sz += 300;
 			res = realloc(res, sz*sizeof(char));
 		}
-		bool bb = x < 0;
-		if (bb)
-			x = -x;
-		res[num + 2] = (x << 9) >> 25;
-		res[num + 2] |= (bb << 7);
+		if (x < 0){
+			x = (~(unsigned int)(-x) + 1);
+		}
+		if (y < 0){
+			y = (~(unsigned int)(-y) + 1);
+		}
+		res[num + 2] = (x << 8) >> 24;
 		res[num + 1] = (x << 16) >> 24;
 		res[num] = (x << 24) >> 24;
-		bb = y < 0;
-		if (bb)
-			y = -y;
-		res[num + 5] = (y << 9) >> 25;
-		res[num + 5] |= (bb << 7);
+		res[num + 5] = (y << 8) >> 24;
 		res[num + 4] = (y << 16) >> 24;
 		res[num + 3] = (y << 24) >> 24;
 		num+=6;
@@ -65,13 +63,11 @@ void savetext(char *name, unsigned char *arr, int num){
 	for (int i = 0; i < num; i+= 6){
 		x = arr[i] + (arr[i + 1] << 8) + (arr[i + 2] << 16);
 		if ((x & (1 << 23)) != 0){
-			x ^= (1 << 23);
-			x = -x;
+			x = -(((~(unsigned int)x + 1) << 8) >> 8);
 		}
 		y = arr[i + 3] + (arr[i + 4] << 8) + (arr[i + 5] << 16);
 		if ((y & (1 << 23)) != 0){
-			y ^= (1 << 23);
-			y = -y;
+			y = -(((~(unsigned int)y + 1) << 8) >> 8);
 		}
 		fprintf(f, "%d %d\n", x, y);
 	}
@@ -106,15 +102,13 @@ void apply(struct intrusive_list *l, void (*op)(struct position_node*, void*), v
 void make(struct intrusive_list *l, unsigned char *arr, int num){
 	int x, y;
 	for (int i = num - 6; i >= 0; i-=6){
-		x = arr[i] + (arr[i + 1] << 8) + (arr[i + 2] << 16);
+		x = arr[i] + (arr[i + 1] << 8) + (arr[i + 2] << 16);	
 		if ((x & (1 << 23)) != 0){
-			x ^= (1 << 23);
-			x = -x;
+			x = -(((~(unsigned int)x + 1) << 8) >> 8);
 		}
 		y = arr[i + 3] + (arr[i + 4] << 8) + (arr[i + 5] << 16);
 		if ((y & (1 << 23)) != 0){
-			y ^= (1 << 23);
-			y = -y;
+			y = -(((~(unsigned int)y + 1) << 8) >> 8);
 		}
 		add_position(l, x, y);
 	}