Write routines to implement two stacks using only one array. Your stack routines should not declare an overflow unless every slot in the array is used.
Format of functions:
Stack CreateStack( int MaxElements ); int IsEmpty( Stack S, int Stacknum ); int IsFull( Stack S ); int Push( ElementType X, Stack S, int Stacknum ); ElementType Top_Pop( Stack S, int Stacknum );where int Stacknum is the index of a stack which is either 1 or 2; int MaxElements is the size of the stack array; and Stack is defined as the following:
typedef struct StackRecord *Stack; struct StackRecord { int Capacity; /* maximum size of the stack array */ int Top1; /* top pointer for Stack 1 */ int Top2; /* top pointer for Stack 2 */ ElementType *Array; /* space for the two stacks */ }Note: Push is supposed to return 1 if the operation can be done successfully, or 0 if fails. If the stack is empty, Top_Pop must return ERROR which is defined by the judge program.
Sample program of judge:
#include <stdio.h> #include <stdlib.h> #define ERROR 1e8 typedef int ElementType; typedef enum { push, pop, end } Operation; typedef struct StackRecord *Stack; struct StackRecord { int Capacity; /* maximum size of the stack array */ int Top1; /* top pointer for Stack 1 */ int Top2; /* top pointer for Stack 2 */ ElementType *Array; /* space for the two stacks */ }; Stack CreateStack( int MaxElements ); int IsEmpty( Stack S, int Stacknum ); int IsFull( Stack S ); int Push( ElementType X, Stack S, int Stacknum ); ElementType Top_Pop( Stack S, int Stacknum ); Operation GetOp(); /* details omitted */ void PrintStack( Stack S, int Stacknum ); /* details omitted */ int main() { int N, Sn, X; Stack S; int done = 0; scanf("%d", &N); S = CreateStack(N); while ( !done ) { switch( GetOp() ) { case push: scanf("%d %d", &Sn, &X); if (!Push(X, S, Sn)) printf("Stack %d is Full!\n", Sn); break; case pop: scanf("%d", &Sn); X = Top_Pop(S, Sn); if ( X==ERROR ) printf("Stack %d is Empty!\n", Sn); break; case end: PrintStack(S, 1); PrintStack(S, 2); done = 1; break; } } return 0; } /* Your function will be put here */Sample Input: 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 EndSample Output:
Stack 2 is Empty! Stack 1 is Full! Pop from Stack 1: 1 Pop from Stack 2: 13 12 11思路 今天中午有人问了我一道和这个差不多的题，我的妈呀，好难啊 看了韩旭大佬的代码 写了写 好疑惑啊 一开始是
int IsEmpty(Stack S,int Stacknum){ if(Stacknum==1) if(S->Top1==-1) return 1; else if(Stacknum==2){ if(S->Top2==S->Capacity) return 1; } return 0; }然后提交一直显示段错误，一条一条找错后来发现
if(Stacknum==1) if(S->Top1==-1) return 1;改成
if(Stacknum==1){if(S->Top1==-1) return 1;}就AC了 后来百度了一下，我想这可能是这个缘故吧，也可能不是， 若有错误，求大佬指出
代码
Stack CreateStack( int MaxElements ){ Stack p=(Stack)malloc(sizeof(struct StackRecord)); p->Array=(int*)malloc(MaxElements*sizeof(int)); p->Top1=-1; p->Top2=MaxElements; p->Capacity=MaxElements; return p; } int IsEmpty(Stack S,int Stacknum){ if(Stacknum==1){if(S->Top1==-1) return 1;} else if(Stacknum==2){ if(S->Top2==S->Capacity) return 1; } return 0; } int IsFull(Stack S){ if(S->Top2-S->Top1==1) return 1; return 0; } int Push(ElementType X, Stack S, int Stacknum){ if(IsFull(S)) return 0; if(Stacknum==1) S->Array[++(S->Top1)]=X; else S->Array[--(S->Top2)]=X; return 1; } ElementType Top_Pop( Stack S, int Stacknum ){ if(IsEmpty(S,Stacknum)) return ERROR; if(Stacknum==1) return S->Array[(S->Top1)--]; else return S->Array[(S->Top2)++]; }