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 1 #include<stdio.h>
2 #include<stdlib.h>
3 struct SNode{
4 int *data;
5 int top;
6 int maxsize;
7 };
8 typedef struct SNode *stack;
9
10 //初始化堆栈函数
11 stack createstack(int maxsize){
12 stack S = (stack)malloc(sizeof(struct SNode));
13 S->data = (int*)malloc(sizeof(int)*maxsize);
14 S->top = -1;
15 S->maxsize = maxsize;
16 return S;
17 }
18
19 //判断堆栈是否为空函数
20 bool Isempty(stack S){
21 return (S->top == -1);
22 }
23
24 //入栈函数
25 void push(stack S, int temp) {
26 S->data[++(S->top)] = temp;
27 }
28
29 //出栈函数
30 void pop(stack S){
31 if(S->top==-1) return;
32 else {
33 S->top--;
34 }
35 }
36
37 int main( ){
38 int M, N, K;
39 scanf("%d%d%d", &M, &N, &K);
40 stack S = createstack(M);
41 while(K--){
42 bool flag = true;
43 int temp = 1, num;
44 for(int i=0; i<N; i++){ //循环读入push sequence的每个数
45 scanf("%d", &num);
46 while(S->top<S->maxsize && flag) //当堆栈不满，且前面的元素均是可能的出栈序列时
47 {
48 if(Isempty(S) || S->data[S->top]!=num) //若堆栈空，或栈顶元素不等于num
49 {
50 push(S, temp++); //将temp按升序压入堆栈
51 }
52 else if(S->data[S->top]==num) //直到栈顶元素等于num
53 {
54 pop(S); //将元素出栈
55 break;
56 }
57 }
58 if(S->top>=S->maxsize) //如果temp一直压到堆栈满，仍未找到符合num的出栈元素
59 {
60 flag = false; //说明该序列不是可能的出栈序列，将flag设为false
61 }
62 }
63 if(flag) printf("YES\n");
64 else printf("NO\n");
65 while(!Isempty(S)) //每个序列判断完，将堆栈清空
66 {
67 pop(S);
68 }
69 }
70 return 0;
71 }
原文地址：https://www.cnblogs.com/shin0324/p/9797085.html