1 files changed, 46 insertions, 0 deletions
diff --git a/514/rails.cpp b/514/rails.cpp
new file mode 100644
index 0000000..d2f373b
--- /dev/null
+++ b/514/rails.cpp
@@ -0,0 +1,46 @@
+#include <iostream>
+#include <stack>
+using namespace std;
+
+bool in(stack<int> s, int num){
+    bool found=false;
+    while(!found && s.size()>0){
+	found=(s.top()==num);
+	s.pop();
+    }
+    return found;
+}
+
+int main(){
+    int num;
+    cin>>num;
+    while(num!=0){
+	stack<int> s, orig;
+	for(int i=num; i>0; i--)
+	    orig.push(i);
+	
+	bool possible=true, end=false;
+
+	while(!end){
+	    int x;
+	    cin>>x;
+	    if(x==0){
+		cout<<endl;
+		end=true;
+	    }
+	    else{
+		for(int i=0; i<num-1 && possible; i++){
+		    while(!in(s, x)){
+			s.push(orig.top());
+			orig.pop();
+		    }
+		    if(x!=s.top())
+			possible=false;
+		    cin>>x;
+		}
+		possible? cout<<"Yes\n" : cout<<"No\n";
+	    }
+	}
+	cin>>num;
+    }
+}