【PTA】6-7 在一个数组中实现两个堆栈 (20分)
函数接口定义：
Stack CreateStack( int MaxSize ); bool Push( Stack S, ElementType X, int Tag ); ElementType Pop( Stack S, int Tag );
其中Tag是堆栈编号，取1或2；MaxSize堆栈数组的规模；Stack结构定义如下：
typedef int Position; struct SNode { ElementType *Data; Position Top1, Top2; int MaxSize; }; typedef struct SNode *Stack;
注意：如果堆栈已满，Push函数必须输出“Stack Full”并且返回false；如果某堆栈是空的，则Pop函数必须输出“Stack Tag Empty”（其中Tag是该堆栈的编号），并且返回ERROR。
裁判测试程序样例：
1 #include <stdio.h> 2 #include <stdlib.h> 3 4 #define ERROR 1e8 5 typedef int ElementType; 6 typedef enum { push, pop, end } Operation; 7 typedef enum { false, true } bool; 8 typedef int Position; 9 struct SNode { 10 ElementType *Data; 11 Position Top1, Top2; 12 int MaxSize; 13 }; 14 typedef struct SNode *Stack; 15 16 Stack CreateStack( int MaxSize ); 17 bool Push( Stack S, ElementType X, int Tag ); 18 ElementType Pop( Stack S, int Tag ); 19 20 Operation GetOp(); /* details omitted */ 21 void PrintStack( Stack S, int Tag ); /* details omitted */ 22 23 int main() 24 { 25 int N, Tag, X; 26 Stack S; 27 int done = 0; 28 29 scanf("%d", &N); 30 S = CreateStack(N); 31 while ( !done ) { 32 switch( GetOp() ) { 33 case push: 34 scanf("%d %d", &Tag, &X); 35 if (!Push(S, X, Tag)) printf("Stack %d is Full! ", Tag); 36 break; 37 case pop: 38 scanf("%d", &Tag); 39 X = Pop(S, Tag); 40 if ( X==ERROR ) printf("Stack %d is Empty! ", Tag); 41 break; 42 case end: 43 PrintStack(S, 1); 44 PrintStack(S, 2); 45 done = 1; 46 break; 47 } 48 } 49 return 0; 50 } 51 52 /* 你的代码将被嵌在这里 */
输入样例：
5
Push 1 1
Pop 2
Push 2 11
Push 1 2
Push 2 12
Pop 1
Push 2 13
Push 2 14
Push 1 3
Pop 2
End输出样例：
Stack 2 Empty
Stack 2 is Empty!
Stack Full
Stack 1 is Full!
Pop from Stack 1: 1
Pop from Stack 2: 13 12 11函数实现细节：
1 Stack CreateStack( int MaxSize ){ 2 Stack S=(Stack)malloc(sizeof(struct SNode)); 3 S->Data=(ElementType *)malloc(MaxSize*sizeof(ElementType)); 4 S->Top1=-1; 5 S->Top2=MaxSize; 6 S->MaxSize=MaxSize; 7 return S; 8 } 9 10 bool Push( Stack S, ElementType X, int Tag ){ 11 if(S->Top1+1==S->Top2){ 12 printf("Stack Full "); 13 return false; 14 } 15 if(Tag==1){ 16 S->Data[++S->Top1]=X; 17 } 18 else{ 19 S->Data[--S->Top2]=X; 20 } 21 return true; 22 } 23 24 ElementType Pop( Stack S, int Tag ){ 25 if(Tag==1){ 26 if(S->Top1==-1){ 27 printf("Stack %d Empty ",Tag); 28 return ERROR; 29 } 30 return S->Data[S->Top1--]; 31 } 32 else if(Tag==2){ 33 if(S->Top2==S->MaxSize){ 34 printf("Stack %d Empty ",Tag); 35 return ERROR; 36 } 37 return S->Data[S->Top2++]; 38 } 39 40 }