实验三
task3_1.cpp
#include <iostream> #include <fstream> #include <array> #define N 5 int main() { using namespace std; array<int, N> x{ 97, 98, 99, 100, 101 }; ofstream out; out.open("data1.dat", ios::binary); if (!out.is_open()) { cout << "fail to open data1.dat\n"; return 1; } // 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 out.write(reinterpret_cast<char*>(&x), sizeof(x)); out.close(); }
结果:
task3_2.cpp
#include <iostream> #include <fstream> #include <array> #define N 5 int main() { using namespace std; array<int, N> x; ifstream in; in.open("data1.dat", ios::binary); if (!in.is_open()) { cout << "fail to open data1.dat\n"; return 1; } // 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 in.read(reinterpret_cast<char*>(&x), sizeof(x)); in.close(); for (auto i = 0; i < N; ++i) cout << x[i] << ", "; cout << "\b\b \n"; }
结果:
修改后
结果:
原因:
录入记事本中的数据中,ab之间有三个空格字符,使用int类型时会将其空格字符自动忽略,而char类型会将空格字符一同录入。
实验四
Vector.hpp
#pragma once #include<iostream> using namespace std; template<typename T> class Vector { public: Vector(int n) :size(n) { data = new T[n]; } Vector(int n,T obj) :size(n) { int i; data = new T[n]; for (i = 0; i < n; i++) data[i] = obj; } Vector(const Vector<T>& a) :size{ a.size } { data = new T[size]; for (int i = 0; i < size; i++) data[i] = a.data[i]; } T& operator[](int i) { return data[i]; } T& at(int i) { return data[i]; } int get_size()const { return size; } friend void output(const Vector<T>& obj) { int i; for (i = 0; i < obj.size; i++) cout << obj.data[i] << ","; cout << endl; } private: int size; T* data; };
task.cpp
#include <iostream> #include "Vector.hpp" void test() { using namespace std; int n; cin >> n; Vector<double> x1(n); for (auto i = 0; i < n; ++i) x1.at(i) = i * 0.7; output(x1); Vector<int> x2(n, 42); Vector<int> x3(x2); output(x2); output(x3); x2.at(0) = 77; output(x2); x3[0] = 999; output(x3); } int main() { test(); }
结果
修改数据后
#include <iostream> #include "Vector.hpp" void test() { using namespace std; int n; cin >> n; Vector<double> x1(n); for (auto i = 0; i < n; ++i) x1.at(i) = i * 0.7; output(x1); Vector<int> x2(n, 16); Vector<int> x3(x2); output(x2); output(x3); x2.at(0) = 66; output(x2); x3[0] = 99; output(x3); } int main() { test(); }
结果
实验五
task_5.cpp
#include <iostream> #include<fstream> #include<string> using namespace std; void output(std::ostream& out) { string a[27][27]; int i, j, n = 0; for (i = 1; i < 27; i++) { a[i][0] = to_string(i); a[0][i] = 97 + n; n++; } for (i = 1; i < 27; i++) { n = i; for (j = 1; j < 27; j++) { if (65 + n > 90) { a[i][j] = 65 + n - 26; } else { a[i][j] = 65 + n; } n++; } } for (i = 0; i < 27; i++) { for (j = 0; j < 27; j++) { cout << a[i][j] << " "; out << a[i][j] << " "; } cout << endl; out << endl; } } int main() { ofstream out; out.open("cipher_ke.txt"); if (!out.is_open()) { cout << "fail to open cipher_key.txt to write" << endl; } output(out); out.close(); }
结果:
标签:int,++,Vector,实验,x2,output,include From: https://www.cnblogs.com/qiumusu/p/16961742.html