02-线性结构4 Pop Sequence (25分)

02-线性结构4 Pop Sequence (25分)
Given a stack which can keep MM numbers at most. Push NN numbers in the order of 1, 2, 3, …, NN 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 MM is 5 and NN 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): MM (the maximum capacity of the stack), NN (the length of push sequence), and KK (the number of pop sequences to be checked). Then KK lines follow, each contains a pop sequence of NN 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

#include <iostream>#include <vector>#include <stack>#include <set>using namespace std;int main(){    int stackSize;    int nums;    int n;    int tempNum;    cin>>stackSize>>nums>>n;    stack<int> s;    set<int> numCan;    bool flag = true;    int arr[1010];    for(int i = 0; i < n; i++){        for(int k = 0; k < nums; k++){            numCan.insert(k+1);        }        for(int q = 0; q <nums;q++){            cin>>arr[q];        }        for(int j = 0; j < nums && flag;j++){            tempNum = arr[j];            for(int p = 1;p <= tempNum && flag;p++) {                if (numCan.find(p) != numCan.end()) {                    if (s.size() < stackSize) {                        s.push(p);                        numCan.erase(p);                    } else {                        flag = false;                        cout << "NO" << endl;                    }                }            }            if(flag){                int temp = s.top();                s.pop();                if(temp != tempNum && flag){                    flag = false;                    cout<<"NO"<<endl;                }            }        }        if(flag){            cout<<"YES"<<endl;        }        flag = true;        numCan.clear();        while(s.size() != 0){            s.pop();        }    }}