Task 3 is done!

2025.04.18/03Ex/solve.c

@@ -0,0 +1,36 @@
+#include "solve.h"
+
+#include <float.h>
+#include <math.h>
+#include <stdio.h>
+
+
+// Interpolation polynomial according to Aitken's scheme
+double t3_solve (const double x_0, const int n, const double * restrict X, double * restrict Y)
+{
+	for (int k = 0; k < n-1; ++k)
+	{
+		double x_j; 
+		double y_j = Y[n-1];
+
+//		printf ("------- K = %d -------\n", k);
+		
+		for (int i = n-2; i >= k; --i)
+		{
+			const double x_i = X[i-k];
+			const double y_i = Y[i];
+			x_j = X[i+1];
+			
+			if (fabs(x_j - x_i) < DBL_EPSILON)
+				return DBL_MAX;
+			
+			Y[i+1] = ((x_0-x_i) * y_j - (x_0-x_j) * y_i) / (x_j - x_i);
+//			printf ("I = %d, f(x%d, ... , x%d) = %lf\n", i, i-k+1, i+2, Y[i+1]);
+
+			y_j = y_i;
+		}
+	}
+
+	return Y[n-1];
+}
+