题意看了老半天，就是说给一个序列[1, n]，看是否是(1, 2, 3, ... n),入栈以后出栈时可以得到的序列。

My Code:

#include 
      
        #include 
       
         using namespace std; const int N = 100007; int st1[N], st2[N]; int main() {
    //freopen("data.in", "r", stdin); int i, top1, top2, n; while(cin >> n) {
    for(i = 0; i < n; i++) {
                cin >> st2[i];         }         top1 = 0; top2 = 0; for(i = 1; i <= n; i++) {
                st1[++top1] = i; while(top1 != 0 && st1[top1] == st2[top2]) {
                    --top1; ++top2;             }         } if(top1)    cout << "Cheater"; else    cout << "Not a proof";         cout << endl;     } return 0; }