数据结构作业3

#include <stdio.h>
#include <stdlib.h>

typedef int DataType;//                                                                                                             come

typedef struct SeqStack{
    int MAXNUM;
    int top;
    DataType *data;
}SeqStack,*PSeqStack;


//1.创建空栈
PSeqStack createEmptyStack_seq(int m){
    PSeqStack pastack = (PSeqStack)malloc(sizeof(SeqStack));
    if(pastack == NULL){printf("顺序栈内存分配失败"); return NULL;};
 
    pastack->data = (DataType *)malloc(sizeof(DataType)*m);
    if(pastack->data == NULL){printf("空间内存分配失败");return NULL;}

    pastack->top = -1;
    pastack->MAXNUM = m;

    return pastack;
}

//2.判断是否为空
int isEmptyStack_seq(PSeqStack pastack){
    return(pastack->top == -1);
}

//3.进栈
int push_seq(PSeqStack pastack, DataType x){
    if (pastack->top >= pastack->MAXNUM-1)
    {
        printf("栈已满！");
        return 0;
    }
    
    
    pastack->data[pastack->top+1] = x;                                                                                       //from
    pastack->top ++;
    
    return 1;

}

//4.出栈
int pop_seq(PSeqStack pastack){
    if (pastack->top == -1)
    {
        printf("空栈操作失败！");
        return 0;
    }
    pastack->top--;
    return 1;
}

//5.取栈顶元素但不删除，返回栈顶数据；
DataType top_seq(PSeqStack pastack){
    if (pastack->top == -1)
    {
        printf("空栈操作失败！");
        return -1;
    }

    return pastack->data[pastack->top];                                                                                               //alonep
    
}