UVa 514 - Rails

挺简单的一道例题。

#include<iostream>#include<stack>#define MAXN 1005using namespace std;int main() {    int N;    while(cin >> N&& N) {        while(1) {            int A = 1, B = 1, Sta[MAXN];            bool ok = true;            stack<int> C;            for(int i = 1; i <= N; i++) {                cin >> Sta[i];                if(!Sta[i]) break;            }            if(!Sta[1]) break;            while(B <= N) {                if(A == Sta[B]) {A++; B++;}                else if(!C.empty()&& C.top() == Sta[B]) {C.pop(); B++;}                else if(A <= N) {C.push(A); A++;}                else {                    ok = false;                    break;                }            }            ok ? cout << "Yes" << endl : cout << "No" << endl;        }        cout << endl;    }    return 0;}