Task 5 is already done

2025.05.02/05Ex/solve.c

@@ -6,65 +6,73 @@
 #include <stdint.h>
 #include <string.h>
 
-int t1_solve (
+int t5_solve (
 		double (*f) (double), 
 		double a, double b, 
 		double eps, int m, double *x
 ) {
-	int it = 0;
-	uint64_t bits;
-	double c = DBL_MAX, y, y_a = f(a), y_b = f(b);
-	bool sgn_a, sgn_b, sgn_c;
+	int it;
+	double c = (a + b) * 0.5;
 
-	memcpy(&bits, &y_a, sizeof(bits));
-	sgn_a = (bits >> 63) & 1;
-	memcpy(&bits, &y_b, sizeof(bits));
-	sgn_b = (bits >> 63) & 1;
-
-	if (fabs(y_a) - eps < DBL_EPSILON)
+	double y_a = f(a);
+	double y_c = f(c);
+	double y_b = f(b);
+	
+	if (is_null(y_a))
 	{
 		*x = a;
 		return 1;
-	} if (fabs(y_b) - eps < DBL_EPSILON)
+	} else if (is_null(y_b))
 	{
 		*x = b;
 		return 1;
+	} else if (is_null(y_c))
+	{
+		*x = c;
+		return 1;
 	}
 
-	if (sgn_a == sgn_b)
-	{
-		*x = DBL_MAX;
+	if (is_equal(a, b))
+		return -1;
+	else if (is_equal(a, c))
+	       return -1;
+	else if (is_equal(b, c))
 		return -1;
-	}
-	
-	for (it = 1; it <= m; ++it)
-	{
-		c = (a + b) * 0.5;
-		y = f(c);
-		
-		memcpy(&bits, &y, sizeof(bits));
-		sgn_c = (bits >> 63) & 1;
-		
-		if (fabs(y) - eps < DBL_EPSILON)
-			break;
-		else if ((fabs(c - a) < DBL_EPSILON) || (fabs(c - b) < DBL_EPSILON))
-			it = m+1;
-		else if (sgn_c == sgn_a)
-		{
-			a = c;
-			y_a = y;
-		} else if (sgn_c == sgn_b)
-		{
-			b = c;
-			y_b = y;
-		}
-	}
-	
-	if (it > m)
-		it = -1;
-	
-	*x = c;
 
-	return it;
+	for (it = 1; it < m+1; ++it)
+	{
+		double *temp_pnt = 0, *inner_max_pnt;
+		const double angle = (c - a) / (y_c - y_a);
+		const double x_new = a - 
+			angle * y_a +
+		       	((((b - c) / (y_b - y_c)) - angle) / (y_b - y_a)) * y_a * y_c;
+		const double y_new = f(x_new);
+
+		if (is_eps(y_new, eps))
+		{
+			*x = x_new;
+			return it;
+		}
+
+		if (
+			is_equal(x_new, a) ||
+			is_equal(x_new, c) ||
+			is_equal(x_new, b)
+		   )
+			return -1;
+
+		inner_max_pnt = fp_abs_max(&c, &b, &y_c, &y_b, &temp_pnt);	
+		*fp_abs_max(&a, inner_max_pnt, &y_a, temp_pnt, &temp_pnt) = x_new;
+		*temp_pnt = y_new;
+	}
+
+	if (it > m)
+		return -2;
+	else
+	{
+		double temp = 0, *temp_x_pnt = fpmax(&c, &b, -y_c, -y_b, &temp);
+		*x = *fpmax(&a, temp_x_pnt, -y_a, temp, &temp);
+		return it;
+	}
 }