//EXERCISE 2.1
//Write a program that reads integers from the standard input until the end of file and then prints the largest and the smallest values
#include<iostream> #include<fstream> using namespace std; int main() { int n,max=0,min=0; cout << "input the biggest number:"<<endl; cin >> n; ifstream fin; fin.open("in.txt"); int *a = new int[n]; if(!fin) { cout <<"failure"<<endl; exit(0); } for(int i =0;i<n;i++) { fin >> a[i]; if(a[max]<a[i]) max =i; if(a[min]>a[i]) min = i; } fin.close(); cout << "the max is" << a[max]<<endl; cout << "the min is" << a[min]<<endl; delete[] a; return 0; }
2.2 Write a program that echoes the standard input to the standard output,except that each tab is replaced by the approriate name of spaces.Assume that tabs are set evey 8 columns,unless the user specifies a different tab setting on the command line.(讲真。。。题目我没看懂)
#include<iostream>
#include<iomanip>
using namespace std;
int main()
{
int a,b,c;
cin >>a>>b>>c;
cout <<setw(8) << a<<endl;
cout <<setw(8) << b<<endl;
cout <<setw(8) << c<<endl;
return 0;
}
2.3 write a function db1that takes an int argument and multiplies it by 2.Pass the argument by reference.
#include<iostream>
using namespace std;
void db1(int&);
int main()
{
int x = 6;
db1(x);
cout << x <<end
return 0;
}
void db1(int& ref)
{
ref = 2 * ref;
}
原文：http://www.cnblogs.com/monica-yuki/p/4909168.html