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("data.txt",ios::binary); if(!out.is_open()){ cout<<"fail to open data1.dat\n"; return 1; } out.write(reinterpret_cast<char *>(&x),sizeof(x)); out.close(); }
task3_2.cpp
#include<iostream> #include<fstream> #include<array> #define N 5 int main(){ using namespace std; array<char,N>x; ifstream in; in.open("data.dat1",ios::binary); if(!in.is_open()){ cout<<"fail to open data1.dat\n"; return 1; } in.read(reinterpret_cast<char *>(&x),sizeof(x)); in.close(); for(auto i=0;i<N;i++) cout<<x[i]<<","; cout<<"\b\b\n"; }
测试截图
char型占1个字节,而int型占4个字节
Vector.hpp
#pragma once #include<iostream> using namespace std; template<typename T> class Vector { public: Vector(int n):size{n} { value=new T[n]; } Vector(int n,T v):size{n} { value=new T[n]; for(int i=0;i<n;i++) value[i]=v; } Vector(const Vector<T> &a):size{a.size} { value=new T[size]; for(int i=0;i<size;i++) value[i]=a.value[i]; } T &operator[](int i) { return value[i]; } int get_size() const { return size; } T &at(int index) { return value[index]; } friend void output(const Vector<T> &a) { for(int i=0;i<a.size;i++) cout<<a.value[i]<<","; cout<<"\b\b\n"; } private: int size; T *value; };
task4.cpp
#include<iostream> #include"vector.h" void test(){ using namespace std; int n; cin>>n; Vector<double> x1(n); for(auto i=0;i<n;i++) x1.at(i)=i*0.6; output(x1); Vector<int> x2(n,88); Vector<int> x3(x2); output(x2); output(x3); x2.at(0)=66; output(x2); x3[0]=666; output(x3); } int main(){ test(); }
测试截图
task5.cpp
#include<fstream> #include<iostream> #include<iomanip> using std::endl; using std::setw; using std::ofstream; void output(std::ostream& out) { out << " "; char n = 'a'; for (int i = 1; i <= 26; ++i, ++n) { out << setw(2) << n; } out << endl; for (int i = 1; i <= 26; ++i) { out << setw(2) << i; if (n == 'Z') { n = 'A'; } else { n = i + 'A'; } for (int j = 1; j <= 26; ++j, ++n) { out << setw(2) << n; if (n == 'Z') { n = 'A' - 1; } } out << endl; } } int main() { output(std::cout); ofstream out; out.open("cipher_key.txt"); if (!out.is_open()) { std::cout << "fail to open file cipher_key.txt.\n"; return 1; } output(out); out.close(); }
测试截图
标签:std,int,Vector,实验,using,include,out From: https://www.cnblogs.com/dingxincheng/p/16961812.html