我编写了以下代码用于将中缀表达式转换为后缀，但显示运行时错误。
错误如下：
输入字符串：a+bc*d 1 [main] infix_to_postfix 7340 cygwin_exception::open_stackdumpfile: 将堆栈跟踪转储到 infix_to_postfix.exe.stackdump
以下是我的代码：
#include<stdio.h>
#include<string.h>
#define size 20
struct stack{
int a[size],top;
int temp[size], tos;
}s;
// Push operation....
void push(struct stack s,int item){
if(s.top >= size-1){
printf("\nStack overflow..\n");
}
else{
s.a[++s.top] = item;
}
}
// Pop operation....
int pop(struct stack s){
if(s.top == -1){
printf("\n..Stack underflow..\n");
}
else {
return s.a[s.top--];
}
}
// function f starts from here. f returns the precedence value of corresponding symbol.
int f(char symbol){
if (symbol == '+' || '-')
return 1;
if (symbol == '*' || '/')
return 2;
if (symbol == '#')
return 0;
char c;
for(c='a'; c<='z'; c++){
if(symbol == c)
return 3;
}
}
int main(){
s.top = -1;
s.a[++s.top] = '#';
int i = 0;
char input[20], polish[21];
char next, temp;
printf("Input string: ");
scanf("%s", input);
strcat(input, '#');
next = input[i++];
while(next != '\0'){
while(f(next) > f(s.a[s.top])){
push(s, next);
next = input[i++];
}
while(f(next) <= f(s.a[s.top])){
temp = pop(s);
strcat(polish, temp);
printf("\nPolish: %s", polish);
}
}
return 0;
}