題干：

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. FINISHFor the first Sample Input, we let train 1 get in, then train 2 and train 3. So now train 3 is at the top of the railway, so train 3 can leave first, then train 2 and train 1. In the second Sample input, we should let train 3 leave first, so we have to let train 1 get in, then train 2 and train 3. Now we can let train 3 leave. But after that we can't let train 1 leave before train 2, because train 2 is at the top of the railway at the moment. So we output "No.".

Hint

Hint

解題報告：

? ? ?剛開始天真的以為直接翻轉數組，如果匹配就YES否則就NO。但是一想這題沒這么簡單，因為比如：我一共要停4輛車，我可以先停三輛，然后出兩輛，然后再進一輛，這樣也是符合題意的。

? ? 別忘了這里用了數據結構，所以任何操作都必須判斷一步棧是否為空。

AC代碼：

#include<bits/stdc++.h>using namespace std; int opr[1005]; int main() {char in[15],out[15];int n;while(~scanf("%d",&n)) {int top = 0;scanf("%s%s",in,out);stack<char > sk;int cur=0;for(int i = 0; i<n; i++) {sk.push(in[i]);opr[++top] = 1;if(sk.size()) {while(sk.size() && sk.top() == out[cur]) {cur++;sk.pop();opr[++top] = 0;}} }if(sk.empty()) {puts("Yes.");for(int i = 1; i<=top; i++) {opr[i] == 1 ? puts("in") : puts("out");}}else puts("No.");puts("FINISH");}return 0 ; }

?

總結

以上是生活随笔為你收集整理的【HDU - 1022】Train Problem I （栈模拟，水题，思维）的全部內容，希望文章能夠幫你解決所遇到的問題。

如果覺得生活随笔網站內容還不錯，歡迎將生活随笔推薦給好友。