实验任务3
task3_1.cpp源码： 1 #include <iostream>
2 #include <fstream>
3 #include <array>
4 #define N 5
5 int main() {
6 using namespace std;
7 array<int, N> x{ 97, 98, 99, 100, 101 };
8 ofstream out;
9 out.open("data1.dat", ios::binary);
10 if (!out.is_open()) {
11 cout << "fail to open data1.dat\n";
12 return 1;
13 }
14 // 把从地址&x开始连续sizeof(x)个字节的数据块以字节数据块方式写入文件data1.txt
15 out.write(reinterpret_cast<char*>(&x), sizeof(x));
16 out.close();
17 }
task3_2.cpp源码：
1 #include <iostream>
2 #include <fstream>
3 #include <array>
4 #define N 5
5 int main() {
6 using namespace std;
7 array<int, N> x;
8 ifstream in;
9 in.open("data1.dat", ios::binary);
10 if (!in.is_open()) {
11 cout << "fail to open data1.dat\n";
12 return 1;
13 }
14 // 从文件流对象in关联的文件data1.dat中读取sizeof(x)字节数据写入&x开始的地址单元
15 in.read(reinterpret_cast<char*>(&x), sizeof(x));
16 in.close();
17 for (auto i = 0; i < N; ++i)
18 cout << x[i] << ", ";
19 cout << "\b\b \n";
20 }
运行截图为：
task3_1中是把从地址&x开始连续sizeof(x)个字节的数据块以字节数据块方式写入文件data1.txt，data1.txt存入a b c d e ，因为int 类型占四个字符的长度，当task3_2中int改为char后，每一个字符的长度只读一次，读到的是a，空格，空格，空格，b，所以输出a， ， ，b。
Vector.hpp源代码：
1 #include <iostream>
2 #include <cassert>
3 using namespace std;
4 template<typename T>
5 class Vector {
6 public:
7 Vector(int n){
8 size = n;
9 p = new T[n];
10 }
11 Vector(int n, int x0){
12 size = n;
13 p = new T[size];
14 for (auto i = 0; i < size; ++i)
15 p[i] = x0;
16 }
17 Vector( Vector<T>& vp){
18 size = vp.size;
19 p = new T[size];
20 for (auto i = 0; i < size; ++i)
21 p[i] = vp.p[i];
22 }
23 ~Vector(){
24 delete[] p;
25 }
26 T& at(int index){
27 assert(index >= 0 && index < size);
28 return p[index];
29 }
30 int get_size() { return size; }
31 T &operator [](int i) {
32 return p[i];
33 }
34 template<typename T1>
35 friend void output(Vector<T1>& x);
36 private:
37 int size;
38 T * p;
39 };
40 template<typename T1>
41 void output(Vector<T1>& x) {
42 for (int i = 0; i < x.get_size(); i++)
43 cout << x.at(i) << " ";
44 cout << endl;
45 }
task4.cpp源代码：
1 #include <iostream>
2 #include "Vector.hpp"
3 void test() {
4 using namespace std;
5 int n;
6 cin >> n;
7 Vector<double> x1(n);
8 for (auto i = 0; i < n; ++i)
9 x1.at(i) = i * 0.7;
10 output(x1);
11 Vector<int> x2(n, 42);
12 Vector<int> x3(x2);
13 output(x2);
14 output(x3);
15 x2.at(0) = 77;
16 output(x2);
17 x3[0] = 999;
18 output(x3);
19 }
20 int main() {
21 test();
22 }
运行截图：
实验任务5
task5.cpp源码: 1 #include <iostream>
2 #include<fstream>
3 #include<iomanip>
4 using namespace std;
5 void output(std::ostream& out) {
6 char a[30][30];
7 int j = 0;
8 a[0][0] = ' ';
9 for (int i = 1; i < 27; i++) {
10 a[0][i] = 'a' + i - 1;
11 a[i][0] = i + '0';
12 }
13 for (int i = 1; i < 27; i++) {
14 for (j = 1; j + i < 27; j++)
15 a[i][j] = a[0][j] - 32 + i;
16 for (; j + i >= 26 && j <= 26; j++)
17 a[i][j] = a[0][j] - 58 + i;
18 }
19 for (int i = 0; i < 27; i++) {
20 if (i != 0)
21 cout << setw(2) << a[i][0] - '0';
22 else
23 cout << " ";
24 for (j = 1; j < 27; j++) {
25 cout <<setw(2)<< a[i][j];
26 }
27 cout << endl;
28 }
29
30 for (int i = 0; i < 27; i++) {
31 if (i != 0)
32 out << setw(2) << a[i][0] - '0';
33 else
34 out << " ";
35 for (j = 1; j < 27; j++) {
36 out << setw(2) << a[i][j] ;
37 }
38 out << endl;
39 }
40 }
41 int main() {
42 ofstream out;
43 out.open("cipher_key.txt");
44 if (!out.is_open()) {
45 cout << "Fail to open the cipher_key.txt" << endl;
46 return 1;
47 }
48 output(out);
49 return 0;
50 }
运行截图：
标签：int,++,Vector,实验,output,include,size From： https://www.cnblogs.com/dyb20030328/p/16939003.html