learn in c++.txt

将一个句子中的单词逆序,先将整个句子逆序,再将句子中的单词逆序.

#include <iostream>
using namespace std;

int main(){
	char c;
	unsigned char cu;
	int i;
	unsigned int iu;
	short int is;
	short iis;
	unsigned short int isu;
	unsigned short iisu;
	long int il;
	long iil;
	unsigned long int ilu;
	unsigned long iilu;
	float f;
	double d;
	long double ld;
	cout
		<< "\n char= " << sizeof(c)
		<< "\n unsigned char= " << sizeof(cu)
		<< "\n int= " << sizeof(i)
		<< "\n unsigned int= " << sizeof(iu)
		<< "\n short= " << sizeof(is)
		<< "\n unsigned short= " << sizeof(isu)
		<< "\n long= " << sizeof(il)
		<< "\n unsigned long= " << sizeof(ilu)
		<< "\n float= " << sizeof(f)
		<< "\n double= " << sizeof(d)
		<< "\n long double=" << sizeof(ld)
		<<endl;
	return 0;
}


#include <iostream>
using namespace std;

void f(int& r)
{
	cout  << "r= " << r <<endl;
	cout << "&r= " << &r <<endl;
	r=5;
	cout << "r= " << r << endl;
} 

int main(){
	int x=47;
	cout << " x= " << x <<endl;
	cout << " &x= " << &x <<endl;
	f(x);
	cout << " x= " << x <<endl;
	
	return 0;
}
#include <iostream>
using namespace std;
const int sz=10;

struct X {int a[sz];};

void print(X* x)
{
	for(int i=0;i<sz;i++)
		cout<< x->a[i]<<' ';
	cout << endl << "---------------------------"<< endl;
}

int main(){
	X x;
	print(&x);
	int* xp=reinterpret_cast<int*>(&x);
	for(int* i=xp;i<xp+sz;i++)
		*i=0;
	print(reinterpret_cast<X*>(xp));
	print(&x);
	
	return 0;
}
#include <iostream>
using namespace std;

int main(int argc,char* argv[]){
	cout << "argc= "<<argc<<endl;
	for(int i=0;i<argc;i++)
		cout << "argv["<<i<<"] = "
			<< argv[i]<<endl;
	
	return 0;
}
#include <iostream>
using namespace std;

#define DF(N) void N() {\
	cout << "function " << #N << " called..." << endl;}

DF(a);DF(b);DF(c);DF(d);DF(e);DF(f);DF(g);

void (*func_table[])()={a,b,c,d,e,f,g};

int main(){
	while(1){
		cout << "press a key from 'a' to 'g' "
			"or 'q' to quit" << endl;
		char c,cr;
		cin.get(c);cin.get(cr);
		if(c=='q')
			break;
		if(c<'a'||c>'g')
			continue;
		(*func_table[c-'a'])();
	}

	return 0;
}