hdacm-1022 Train Problem I
Problem Description
As the new term comes, the Ignatius Train Station is very busy nowadays. A lot of student want to get back to school by train(because the trains in the Ignatius Train Station is the fastest all over the world ^v^). But here comes a problem, there is only one railway where all the trains stop. So all the trains come in from one side and get out from the other side. For this problem, if train A gets into the railway first, and then train B gets into the railway before train A leaves, train A can't leave until train B leaves. The pictures below figure out the problem. Now the problem for you is, there are at most 9 trains in the station, all the trains has an ID(numbered from 1 to n), the trains get into the railway in an order O1, your task is to determine whether the trains can get out in an order O2.
Input
The input contains several test cases. Each test case consists of an integer, the number of trains, and two strings, the order of the trains come in:O1, and the order of the trains leave:O2. The input is terminated by the end of file. More details in the Sample Input.
Output
The output contains a string "No." if you can't exchange O2 to O1, or you should output a line contains "Yes.", and then output your way in exchanging the order(you should output "in" for a train getting into the railway, and "out" for a train getting out of the railway). Print a line contains "FINISH" after each test case. More details in the Sample Output.
Sample Input
3 123 321
3 123 312
Sample Output
Yes.
in
in
in
out
out
out
FINISH
No.
FINISH
源代码
#include<iostream>
#include<stack>
#include<string>
#include<vector>
using namespace std;
int trainproblem1(string in,string out,int n);
vector<string> svec;
void main()
{
string str1,str2;
int number;
int i,j;
bool flag=0;
//while(!cin.eof())
while(cin>>number)
{
//cin>>number>>str1>>str2;
cin>>str1>>str2;
int number1=number*2;
flag=trainproblem1(str1,str2,number);
if(flag==1)
{
cout<<"Yes."<<endl;
for(vector<int>::size_type ix=0;ix<number1;ix++)
cout<<svec[ix]<<endl;
}
else
{
cout<<"No."<<endl;
}
cout<<"FINISH"<<endl;
flag=0;
svec.clear();
fflush(stdin);
}
}
int trainproblem1(string in,string out,int n)
{
stack<int> intStack;
int i=0,k=0;
while(i<n)
{
intStack.push(in[i++]);
svec.push_back("in");
while(!intStack.empty() && intStack.top()==out[k])
{
intStack.pop();
svec.push_back("out");
k++;
}
}
if(intStack.empty())
return 1;
else return 0;
}
真是惭愧，栈学的太烂。参考同学的代码整了好久才搞出来。。
问题总结：
1：需要深刻理解栈的应用。
2：需要多次输入数据时，记得清空上次遗留数据。
3：格式错误需注意。
4：疑问?The input is terminated by the end of file.使用while(!cin.eof())不知道为何会WA?
网上解答：while(!cin.eof()) //直至按ctrl+z键退出！
PS：The input is
terminated by the end of file
统一使用
int x；
while（cin>>x）
{
}
return 0；