两个任务
·编程替代strcat()函数
·在字符串中查找指定的第一个字母位置

#include<iostream>
#include<string>
using namespace std;
void main()
{
	int a,i,l,m,n;
	char ch;
	cout<<"in this system, you have two choices to feel the magic of c++:"<<endl;
	cout<<"1,we can use this procedure to replace of strcat()"<<endl;
	cout<<"2,to find the position of a letter in a character"<<endl;
	cout<<"other number,quit"<<endl;
while(1)
{
	cout<<"press your choice(1, 2 or other number)"<<endl;
	cin>>a;
    ch=getchar();
	if(a==1)
	{
		char stra[15]={0};
		char *a=stra;
		char strb[15]={0};
		char *b=strb;
	    cout<<"please input stra: ";
	    gets(stra);
	    cout<<"please input strb: ";
	    gets(strb);
		m=strlen(strb);
		n=strlen(stra);
		for(i=0;i<m;i++)
		{
			ra[n+1+i]=b[i];
			a[n]=' ';
		}
	    cout<<a<<endl;
	}
	else if(a==2)
	{
		char strc[10];
	    char x,*p;
		p=strc;
		cout<<"please input a retrieved character :"<<endl;
        cin>>strc;
		l=strlen(strc);
		cout<<"\""<<*p<<"\" length is: "<<l<<endl;
		cout<<"please input a letter :"<<endl;
		cin>>x;
		for(i=0;p[i]!='\0';i++)
		{
			if(p[i]==x) break;
		}
		if(i<l)
			cout<<"the first position of the letter is :"<<i+1<<endl;
		else
		    cout<<"no position in"<<strc<<endl;
	}
    else
		break;

}
}