Infix to Postfix Converter
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using namespace std;
int priority(char ch) {
switch (ch)
{
case '-':
case '+':
return 0;
case '*':
case '/':
return 1;
case '^':
return 2;
default:
return -1;
}
}
std::string to_postfix(std::string infix) {
infix = '(' + infix + ')';
string res = "";
vector<char> st;
for(auto ch : infix) {
if(ch == '(') st.push_back(ch);
else if(ch == ')') {
while(st.size() and st.back() != '(') {
res.push_back(st.back()); st.pop_back();
}
st.pop_back();
} else if(isdigit(ch)) {
res.push_back(ch);
} else {
while(priority(st.back()) >= priority(ch)) {
res.push_back(st.back()); st.pop_back();
}
st.push_back(ch);
}
}
return res;
}
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