Task 8 is done

2025.05.09/08Ex/solve.c

@@ -0,0 +1,47 @@
+#include "solve.h"
+
+#include <math.h>
+#include <float.h>
+
+#define MAX_ITER 30
+
+int t8_solve (
+		double (*f) (double), 
+		double a, double b,
+		double eps, double *res
+) {
+	int it;
+
+	double n = 1;
+	double h = (b - a);
+	double integ_n = (f(a) + f(b)) * h*0.5;
+
+	for (it = 1; it <= MAX_ITER; ++it)
+	{
+		double x = a + h*0.5;
+		double integ_2n = 0;
+	
+		for (int i = 0; i < n; i++)
+		{
+			integ_2n += f(x);
+			x += h;
+		}
+
+		h *= 0.5;
+		integ_2n = integ_2n * h + integ_n * 0.5;
+
+		if (fabs(integ_2n - integ_n) < eps)
+			break;
+		
+		integ_n = integ_2n;
+		n *= 2;
+	}
+
+	if (it > MAX_ITER) 
+		return -1;
+	
+	*res = integ_n;
+
+	return n;
+}
+