PAT甲级1051 栈的模拟

题目

1051 Pop Sequence (25)（25 分）
Given a stack which can keep M numbers at most. Push N numbers in the order of 1, 2, 3, …, N and pop randomly. You are supposed to tell if a given sequence of numbers is a possible pop sequence of the stack. For example, if M is 5 and N is 7, we can obtain 1, 2, 3, 4, 5, 6, 7 from the stack, but not 3, 2, 1, 7, 5, 6, 4.

Input Specification:

Each input file contains one test case. For each case, the first line contains 3 numbers (all no more than 1000): M (the maximum capacity of the stack), N (the length of push sequence), and K (the number of pop sequences to be checked). Then K lines follow, each contains a pop sequence of N numbers. All the numbers in a line are separated by a space.

Output Specification:

For each pop sequence, print in one line “YES” if it is indeed a possible pop sequence of the stack, or “NO” if not.

Sample Input:

5 7 5
1 2 3 4 5 6 7
3 2 1 7 5 6 4
7 6 5 4 3 2 1
5 6 4 3 7 2 1
1 7 6 5 4 3 2
Sample Output:

YES
NO
NO
YES

NO

题解：

#include
#include//前两位不能有6，7,7不能在5，6之前
#include
using namespace std;
int main(){
  int m,n,k;
  cin>>m>>n>>k;


  for(int i=0;ibool flag=false;
    stack<int> s;
    vector<int> v(n);//0~size-1
    for(int j=0;jscanf("%d",&v[j]);
  }
    int index=0;
    for(int j=1;j<=n;j++){
      s.push(j);
      if(s.size()>m) break;
      while(!s.empty()&&s.top()==v[index]){
        s.pop();
        index++;
      }
    }
    if(index==n) flag=true;
    if(flag) printf("YES\n");
    else printf("NO\n");

  }
  return 0;
}

这题想不到具体实现，还是参考柳神的，等手机好了，我要去扫她的红包：
https://www.liuchuo.net/archives/2232

其他思路可以看这边：https://www.nowcoder.com/questionTerminal/597a931ab1794139835ad2991faeab2d