學到這裏是我學編程以來最歡樂的一個內容,因爲每次看到有關逆波蘭表達式的內容都會看到一句至理名言——“想要出名,不但要有牛逼的成就,名字還要起的朗朗上口!”。哈哈,可憐的Jan Lukasiewicz,是不是應該念做簡.盧卡斯維克斯?管他媽的! 逆波蘭表達式不懂的去度娘之!
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <ctype.h>
#define MAX_STACK_SIZE 20
#define STACKINCREMENT 10
#define MAXBUFFER 10
typedef double ElemType;
typedef struct SqStack
{
ElemType * base;
ElemType * top;
int stacksize;
}SqStack;
void Init(SqStack* s)
{
s->base=(ElemType *)malloc(MAX_STACK_SIZE*sizeof(ElemType));
if(!s->base)exit(0);
s->top=s->base;
s->stacksize=MAX_STACK_SIZE;
};
void Push(SqStack * s,ElemType e)
{
if (s->top-s->base >=s->stacksize)
{
s->base=(ElemType *)realloc(s->base,(MAX_STACK_SIZE+STACKINCREMENT)*sizeof(ElemType));
if(!s->base)exit(0);
}
(s->top)++;
*(s->top)=e;
}
void Pop(SqStack * s,ElemType * e)
{
if (s->top==s->base)return;
*e=*(s->top);
(s->top)--;
}
int main(void)
{
SqStack s;
char c;
double n1,n2;
char str[MAXBUFFER];
int i=0;
Init(&s);
printf("請輸入正確的逆波蘭表達式,數字、符號之間用空格隔開!以#結束輸入:\n");
scanf("%c",&c);
while (c!='#')
{
while (isdigit(c))
{
if(c!=' ')
{
str[i++]=c;
str[i]='\0';
scanf("%c",&c);
}
if(c==' ')
{
int temp=atof(str);
Push(&s,temp);
i=0;
break;
}
}
switch(c)
{
case '+':
Pop(&s,&n1);
Pop(&s,&n2);
Push(&s,n1+n2);
break;
case '-':
Pop(&s,&n1);
Pop(&s,&n2);
Push(&s,n2-n1);
break;
case '*':
Pop(&s,&n1);
Pop(&s,&n2);
Push(&s,n1*n2);
break;
case '/':
Pop(&s,&n1);
Pop(&s,&n2);
if (n1!=0)
{
Push(&s,n2/n1);
}
else
{
printf("分母不能爲零,sb!");
system("pause");
return -1;
}
break;
}
scanf("%c",&c);
}
Pop(&s,&n1);
printf("最終的結果爲:%f\n",n1);
system("pause");
return 0;
}