模拟堆栈 实现简单的加减乘除 差错望大家指出谢谢
#include<iostream>
#include<string.h>
int result(int len,char * str)
{
int result=0;
char * fuhao=new char [len];
int * shuzi=new int [len];
memset (fuhao,0,sizeof(char )*len);
memset (shuzi,0,sizeof(int )*len);
int shuzitop=-1;
int fuhaotop=-1;
for(int i=0;i<len;i++)
{
if('0'<=str[i]<='9')
shuzi[++shuzitop]=str[i]-'0';
if(str[i]=='-'||str[i]=='+'||str[i]=='*'||str[i]=='/')
{
if(str[i]=='*')
{
int num1=shuzi[shuzitop];
int num2=str[++i];
num1*=num2;
shuzi[shuzitop]=num1;
}
if(str[i]=='/')
{
int num1=shuzi[shuzitop];
int num2=str[++i];
num1/=num2;
shuzi[shuzitop]=num1;
}
else
fuhao[++fuhaotop]=str[i];
}
}
while(fuhaotop!=-1)
{
int a=shuzi[shuzitop--];
int b=shuzi[shuzitop];//此处报错了
if(fuhao[fuhaotop--]=='+')
{
b+=a;
shuzi[shuzitop]=b;
}
if(fuhao[fuhaotop--]=='-')
{
b+=a;
shuzi[shuzitop]=b;
}
}
result=shuzi[shuzitop];
delete [] shuzi;
delete [] fuhao;
return result;
}
void main()
{
char *a="1+2";
printf("the result is :%d ",result(5,a));
}
[解决办法]
while(fuhaotop!=-1 &&(fuhaotop >= 0))
[解决办法]
#include<iostream>
#include<string.h>
using namespace std;
int result(int len,char * str)
{
int sum=0;
char * fuhao=new char [len];
int * shuzi=new int [len];
memset (fuhao,0,sizeof(char )*len);
memset (shuzi,0,sizeof(int )*len);
int shuzitop=0;
int fuhaotop=0;
for(int i=0;i<len;i++) {
switch(str[i]){
case '0':case '1':case '2':case '3':case '4':
case '5':case '6':case '7':case '8':case '9':
shuzi[shuzitop]=str[i]-'0';shuzitop++;break;
case '*':case '/':
switch(str[i]){
case '*': shuzi[shuzitop] *= str[i+1]-'0';break;
case '/':shuzi[shuzitop] /= str[i+1]-'0'; break;
}
++i;break;
case '+':case '-':
fuhao[fuhaotop]=str[i];
fuhaotop++;
break;
}
}
sum = shuzi[0];
for(int i=1;i<shuzitop;++i){
switch(fuhao[i-1]){
case '+':sum += shuzi[i];break;
case '-':sum -= shuzi[i];break;
}
}
delete [] shuzi;
delete [] fuhao;
return sum;
}
void main()
{
char *a="1+2";
cout<<"the result is :"<<result(5,a)<<endl;
}
