# infix [] -> 中缀表达式 ; s2[] -> 栈的顺序表 ; top2 -> 栈顶指针
void infixToPostFix(char infix[ ], char s2[ ], int &top2)
{
char s1[maxSize]; #s1 辅助栈
int top1 = -1;
int i=0;
while(infix[i] != ' ')
{
if('0' <= infix[i] && infix[i] <= '9')
{
s2[++top2] = infix[i]; //入栈
++i;
}
else if(infix[i] == '(')
{
s1[++top1] = '(';
++i;
}
else if (infix[i] == '+' || infix[i] == '-' ||
infix[i] == '*' || infix[i] == '/')
{
if(top1 == -1 || s1[top1] == '(' || #当栈顶为空
getPriority(infix[i]) > getPriority(s1[top1])) 当前优先级 > 栈顶优先级
{
s1[++top1] = infix[i];
++i;
}
else
s2[++top2] = s1[top1--]; #将运算符入栈到s2中
}
else if(infix[i] == ')')
{
while(s1[top1] != '(') #当遇到右括号时
s2[++top2] = s1[top1--];
--top1;
++i;
}
}
while(top1 != -1)
s2[++top2] = s1[top--];
}