02-线性结构4 Pop Sequence (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

#include <stdlib.h>
#include <cstdio>
const int maxsize = 1001;
struct SNode {
    int* data;
    int top;
    int MaxSize;
};

typedef struct SNode *Stack;
 
Stack CreateStack( int MaxSize ) {
    Stack s = (Stack) malloc(sizeof(struct SNode));
    s->data = (int* ) malloc(MaxSize * sizeof(int));
    s->top = -1;
    s->MaxSize = MaxSize;
    return s; 
}

bool isFull( Stack s ) {
    return (s->top == s->MaxSize-1);
}
bool isEmpty( Stack s ) {
    return (s->top == -1);
}

bool push( Stack s, int x) {
    if( isFull(s) ) {
        return false;
    }
    else {
        s->data[++(s->top)] = x;
        return true;
    }
}

int pop( Stack s ) {
    return s->data[(s->top)--];
}


int main() {
    int m, n, k, a[maxsize];
    scanf("%d %d %d", &m, &n, &k);
    
    while(k--) {
        Stack s1 = CreateStack(m);
        for(int i=0; i<n; i++) {
            scanf("%d", &a[i]);
        }
        int j = 0, flag;
        for(int i=1; i<=n; i++) {
            flag = push(s1, i);
            if(!flag) break;
            while(!isEmpty(s1) && a[j] == s1->data[s1->top]) {
                j++;
                pop(s1);
            }
        }
        if(flag == false) {
            printf("NO\n");
        }
        else if(isEmpty(s1)) {
            printf("YES\n");
        }
        else printf("NO\n");
        
        
            
        
        
        
    }
    
    
    
    
}