esercizi lezione 7

esercitazioni/bisezione_iterativa.cpp

@@ -0,0 +1,52 @@
+#include <iostream>
+#include <cmath>
+#include <limits>
+
+using namespace std;
+
+const double precision = numeric_limits<double>::epsilon();
+
+// calcola la radice nell'intervallo [a, b], se esiste,
+// della funzione f(x) definita a tempo di scrittura
+// -1 se non sono presenti radici nell'intervallo
+double bisezione(double a, double b, double epsilon);
+
+// definisci sotto
+double f(double x);
+
+int main() {
+	// cout << precision;  // DEBUGGING
+	double a, b;
+	double res;
+
+	cout << "Precisione (minore possibile): " << precision << endl;
+	do {
+		cout << "Inserisci a e b: "; cin >> a >> b;
+		res = bisezione(a, b, precision);
+	} while (res == -1.0);
+
+	cout << "La radice di f(x) nell'intervallo [" << a << ", " << b << "] è: " << res << endl;
+}
+
+// cambia il corpo di questa funzione
+double f(double x) {
+	// return exp(x) - x*x - 2.0;
+	return exp(x);
+}
+
+double bisezione(double a, double b, double epsilon) {
+	if (f(a)*f(b) > 0.0)
+		return -1;
+
+	double c, f_c;
+	while (fabs(a-b) > epsilon) {
+		c = (a+b)/2.0; f_c = f(c);
+		if (f_c >= 0.0-epsilon && f_c <= 0.0+epsilon)
+			return c;
+		if (f_c*f(a) < 0.0)
+			b = c;
+		else if (f_c*f(b) < 0.0)
+			a = c;
+	}
+	return -1;
+}

esercitazioni/codice_car2.cpp

@@ -0,0 +1,13 @@
+#include <iostream>
+
+using namespace std;
+
+int main() {
+	int cod;
+	cin >> cod;
+
+	cod = cod < int(' ') ? ' ' : cod;
+	cod = cod > int('~') ? '~' : cod;
+	cout << static_cast<char>(cod) << endl;
+	return 0;
+}

esercitazioni/div_reale3.cpp

@@ -0,0 +1,15 @@
+#include <iostream>
+#include <iomanip>
+
+using namespace std;
+
+int main() {
+	int a, b;
+	double a_real;
+
+	cout << "[a/b] -> inserisci a: "; cin >> a;
+	cout << "[a/b] -> inserisci b: "; cin >> b;
+	a_real = a;
+	cout << setprecision(15) << a_real/b << endl;	
+	return 0;
+}

esercitazioni/funzioni_car.cpp

@@ -0,0 +1,61 @@
+#include <iostream>
+#include <ctype.h>
+
+using namespace std;
+
+const char MIN_CHAR = ' ';
+const char MAX_CHAR = '~';
+
+bool alfanum(char c) ;
+bool alfabetico(char c) ;
+bool cifra_dec(char c) ;
+bool cifra_esadec(char c) ;
+bool minuscolo(char c) ;
+bool maiuscolo(char c) ;
+
+int main() {
+	char c;
+	cin >> c;
+
+	cout << "alfanum alfabetico dec hex minusc maiusc" << endl;
+
+	cout << alfanum(c) << " ";
+	cout << alfabetico(c) << " ";
+	cout << cifra_dec(c) << " ";
+	cout << cifra_esadec(c) << " ";
+	cout << minuscolo(c) << " ";
+	cout << maiuscolo(c) << " ";
+	cout << endl;
+
+	cout << (bool)isalnum(c) << " ";
+	cout << (bool)isalpha(c) << " ";
+	cout << (bool)isdigit(c) << " ";
+	cout << (bool)isxdigit(c) << " ";
+	cout << (bool)islower(c) << " ";
+	cout << (bool)isupper(c) << " ";
+	cout << endl;
+}
+
+bool alfanum(char c) {
+	return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || (c >= '0' && c <= '9');
+}
+
+bool alfabetico(char c) {
+	return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z');
+}
+
+bool cifra_dec(char c) {
+	return (c >= '0' && c <= '9');
+}
+
+bool cifra_esadec(char c) {
+	return (c >= '0' && c <= '9') || (c >= 'A' && c <= 'F') || (c >= 'a' && c <= 'f');
+}
+
+bool minuscolo(char c) {
+	return (c >= 'a' && c <= 'z');
+}
+
+bool maiuscolo(char c) {
+	return (c >= 'A' && c <= 'Z');
+}

esercitazioni/funzioni_reali.cpp

@@ -0,0 +1,46 @@
+#include <iostream>
+#include <cmath>
+
+using namespace std;
+
+double val_assoluto(double);
+double arrotonda_per_eccesso(double);
+double arrotonda_per_difetto(double);
+
+int main() {
+	double n;
+	cin >> n;
+
+	cout << "fabs ceil floor" << endl;
+	cout << fabs(n) << " ";
+	cout << ceil(n) << " ";
+	cout << floor(n) << " ";
+	cout << endl;
+
+	cout << val_assoluto(n) << " ";
+	cout << arrotonda_per_eccesso(n) << " ";
+	cout << arrotonda_per_difetto(n) << " ";
+	cout << endl;
+}
+
+double val_assoluto(double n) {
+	return n < 0 ? -1*n : n;
+}
+
+double arrotonda_per_eccesso(double n) {
+	if (val_assoluto(n)-static_cast<int>(val_assoluto(n)) == 0)
+		return n;
+
+	return n > 0 ?
+			static_cast<int>(n)+1
+			: static_cast<int>(n);
+}
+
+double arrotonda_per_difetto(double n) {
+	if (val_assoluto(n)-static_cast<int>(val_assoluto(n)) == 0)
+		return n;
+
+	return n > 0 ?
+			static_cast<int>(n)
+			: static_cast<int>(n)-1;
+}

esercitazioni/int_reale_int.cpp

@@ -0,0 +1,15 @@
+#include <iostream>
+#include <iomanip>
+
+using namespace std;
+
+int main() {
+	int a;
+	cin >> a;
+
+	float b = float(a);
+
+	int c = int(b);
+
+	cout << setprecision(20) << a << " " << b << " " << c << endl;
+}

esercitazioni/numero_n_cifre.cpp

@@ -0,0 +1,24 @@
+#include <iostream>
+#include <cmath>
+#include <stdlib.h>
+#include <time.h>
+
+using namespace std;
+
+// return random number in range [min, max]
+int rand_in_range(int min, int max);
+
+int main() {
+	int num_cifre;
+	cin >> num_cifre;
+
+	int max_num = pow(10, num_cifre);
+	// cout << max_num << endl;
+
+	srand(time(NULL));
+	cout << rand_in_range(1, max_num);
+}
+
+int rand_in_range(int min, int max) {
+	return rand()%(max-min) + min;
+}

esercitazioni/numero_razionale.cpp

@@ -0,0 +1,32 @@
+#include <iostream>
+
+using namespace std;
+
+int main() {
+	double num;
+	cin >> num;
+
+	int d = 1;  // denominatore
+	double n = num;  // numeratore
+	while (n-static_cast<int>(n) != 0){
+		d *= 10;
+		n *= 10;
+	}
+
+	cout << n << " " << d << endl;
+
+	// algoritmo di Euclide
+	int a = d, b = n;
+	int mod;
+	while (b) {
+		mod = a%b;
+		a = b;
+		b = mod;
+	}
+
+	cout << a << endl;
+
+	n /= a; d /= a;
+
+	cout << num << " = " << n << "/" << d << endl;
+}