esperimenti stringhe, matrici, vettori dinamici, struct e file binari

esercitazioni/carica_struct_in_ram.cpp

@@ -0,0 +1,32 @@
+#include <iostream>
+#include <fstream>
+
+using namespace std;
+
+struct partita_t {
+	char nome[20];
+	int tempo;
+	int progresso;
+};
+
+void stampa(const partita_t &p) {
+	cout << "Nome: " << p.nome << endl;
+	cout << "Tempo: " << p.tempo << endl;
+	cout << "Progresso: " << p.progresso << endl;
+}
+
+bool carica(partita_t &p, const char filename[]) {
+	ifstream f(filename);
+	if (!f)
+		return false;
+	f.read(reinterpret_cast<char *>(&p), sizeof(partita_t));
+	f.close();
+	return static_cast<bool>(f);
+}
+
+int main() {
+	partita_t p1;
+	carica(p1, "partita.dat");
+	stampa(p1);
+	return 0;
+}

esercitazioni/copia_struct.cpp

@@ -0,0 +1,41 @@
+#include <iostream>
+
+using namespace std;
+
+struct point {
+	int x;
+	int y;
+};
+
+void stampa (point &p) {
+	cout << p.x << " " << p.y << endl;
+}
+
+struct vect {
+	int _[10];
+};
+
+void stampa(vect &v) {
+	for (int i=0; i<10; i++)
+		cout << v._[i] << " ";
+	cout << endl;
+	return;
+}
+
+int main() {
+	point p1, p2;
+	p1 = {1, 2};
+	stampa(p1);
+	stampa(p2);
+	cout << endl;
+	p2 = p1;
+	stampa(p1);
+	stampa(p2);
+	cout << endl;
+
+	vect v = {{1, 2, 3, 4, 5}};
+	vect c;
+	c = v;
+	stampa(v);
+	stampa(c);
+}

esercitazioni/copia_vettore.cpp

@@ -0,0 +1,21 @@
+#include <iostream>
+
+using namespace std;
+
+void copia_vett(const int* const src, int n, int* &dst) {
+	dst = new int[n];
+	for (int i=0; i<n; i++)
+		dst[i] = src[i];
+	return;
+}
+
+int main() {
+	const int a[3] = {1, 2, 3};
+	int* b = NULL;
+	copia_vett(a, 3, b);
+	for (int i=0; i<3; i++)
+		cout << b[i] << " ";
+	cout << endl;
+	delete[] b;
+	return 0;
+}

esercitazioni/len_stringa.cpp

@@ -0,0 +1,11 @@
+#include <iostream>
+
+using namespace std;
+
+int main() {
+	const char s[] = "test_prova";  // 10 caratteri
+	int len;
+	for (len=0; s[len] != '\0'; len++) ;
+	cout << "La stringa ha " << len << " caratteri" << endl;
+	return 0;
+}

esercitazioni/salva_struct_in_memoria.cpp

@@ -0,0 +1,32 @@
+#include <iostream>
+#include <fstream>
+
+using namespace std;
+
+struct partita_t {
+	char nome[20];
+	int tempo;
+	int progresso;
+};
+
+bool salva(const partita_t &p, const char filename[]) {
+	ofstream f(filename);
+	if (!f)
+		return false;
+
+	f.write(reinterpret_cast<const char *>(&p), sizeof(p));	
+
+	f.close();
+	return static_cast<bool>(f);
+}
+
+int main() {
+	partita_t p1_g1 =
+		{
+			"Francesco",
+			10,
+			5
+		};
+	salva(p1_g1, "partita.dat");
+	return 0;
+}

esercitazioni/test_matrici.cpp

@@ -0,0 +1,26 @@
+#include <iostream>
+
+using namespace std;
+
+const int DIM = 4;
+
+int calcola_diff_diag(const int m[][DIM], int dim) {
+	int d_princ = 0;
+	int d_sec = 0;
+	for (int i = 0; i<dim; i++) {
+		d_princ += m[i][i];
+		d_sec += m[i][dim-i-1];
+		// cout << i << " " << dim-i-1 << endl;
+	}
+	cout << d_princ << " " << d_sec << endl;
+	return d_princ-d_sec;
+}
+
+int main() {
+	const int m[][DIM]=	{{1, 2, 3, 4},
+						 {2, 3, 4, 5},
+						 {2, 3, 4, 5},
+						 {2, 3, 4, 5},
+						};
+	cout << calcola_diff_diag(m, DIM);
+}

esercitazioni/test_stringa.cpp

@@ -0,0 +1,10 @@
+#include <iostream>
+
+using namespace std;
+
+int main() {
+	char stringa[] = "parolamoltolungaallocamemoria";
+	cout << "stringa contiene: " << stringa << endl;
+	cout << "Inerisci una parola: "; cin >> stringa;
+	cout << "Hai inserito \""<<stringa<<"\" come parola" << endl;
+}