02-线性结构4. Pop Sequence (25)

时间限制

100 ms

内存限制

65536 kB

代码长度限制

8000 B

判题程序

Standard

作者

CHEN, Yue

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 51 2 3 4 5 6 73 2 1 7 5 6 47 6 5 4 3 2 15 6 4 3 7 2 11 7 6 5 4 3 2

Sample Output:

YESNONOYESNO

自己写的毛病很多，终于改好了。最大的问题是每次测试完数据后需要清空栈

#include <iostream>#include <malloc.h>#define MAX 1001using namespace std;typedef struct node{    int data;    struct node *next;}StackNode,*LinkStack;LinkStack createStack(){    LinkStack ls;    ls=NULL;    return ls;}void pushStack(LinkStack &ls,int data){    StackNode *stNode;    stNode = (StackNode*)malloc(sizeof(StackNode));    stNode->data=data;    stNode->next=ls;    ls=stNode;}int popStack(LinkStack &ls){    int data;    StackNode *node;    if(ls!=NULL)    {        data=ls->data;        node=ls;        ls=ls->next;        free(node);        return data;    }    return 0;}int topStackNode(LinkStack ls){    if(ls!=NULL)    {        return ls->data;    }    return 0;}void clearStack(LinkStack &ls){    while(topStackNode(ls))        popStack(ls);}int main(){    int m,n,k,i,num;    int stac[MAX];    LinkStack ls;    cin>>m>>n>>k;    while(k--)    {        ls=createStack();        num=0;        int uu=0;        for(i=0;i<n;i++)        {            cin>>stac[i];            if(stac[i]>uu)                uu=stac[i];        }        int tmp=0,sum_num=0;        int flag=1;        for(i=1;i<=n;i++)        {            if(uu>n)            {                flag=0;                break;            }            flag=1;            if(sum_num==m)            {                if(topStackNode(ls)==stac[tmp])                {                    popStack(ls);                    sum_num--;                    tmp++;                }                else                {                    flag=0;                    break;                }            }            pushStack(ls,i);            //cout<<"push: "<<i<<endl;            sum_num++;            for(int j=tmp;j<n;j++)            {                if(topStackNode(ls)==0||topStackNode(ls)<stac[j])                    break;                else if(topStackNode(ls)==stac[j])                {                    //cout<<"pop: "<<topStackNode(ls)<<endl;                    popStack(ls);                    sum_num--;                    tmp++;                }else if(topStackNode(ls)>stac[j])                {                    flag=0;                    break;                }            }            if(flag==0)                break;        }        if(flag==1&&tmp==n)            cout<<"YES\n";        else            cout<<"NO\n";        clearStack(ls);    }    return 0;}

建议参考:

#include<iostream>  #include<stack>  using namespace std;int main(){    int M; //maximum capacity of the stack      int N; //the length of push sequence      int K; //the number of pop sequence to be checked      cin >> M >> N >> K;    int i, j;    int input, temp;    bool flag = true;    stack<int> sta;    for (i = 0; i < K; i++)    {        temp = 1;        flag = true;        for (j = 0; j < N; j++)        {            cin >> input;            while (sta.size() <= M && flag)            {                if (sta.empty() || sta.top() != input)                {                    sta.push(temp++);                }                else if (sta.top() == input)                {                    sta.pop();                    break;                }            }            if (sta.size() > M)            {                flag = false;            }        }        if (flag)            cout << "YES" << endl;        else            cout << "NO" << endl;        while (!sta.empty())            sta.pop();    }    return 0;}