//
// Created by 高楚楚 on 2023/8/17.
//

#ifndef LEETCODE_SOLUTION66_H
#define LEETCODE_SOLUTION66_H
#include "bits/stdc++.h"
using namespace std;

class solution66 {
public:
    int calculate(string s) {
        vector<int>num;
        //为了防止第一个数是负数
        num.emplace_back(0);
        vector<char>op;
        bool flag=false;
        string ns="";
        for(int i=0;i<s.size();i++){
            if(s[i]==' ')
                continue;
            ns+=s[i];
        }
        int n=ns.size();
        for(int i=0;i<n;i++){
           if(ns[i]=='('){
                if(ns[i+1]=='-'||ns[i+1]=='+'){
                    num.emplace_back(0);
                }
                op.emplace_back(ns[i]);
            }
            else{
                if(isdigit(ns[i])){
                    int m=0;
                    while(isdigit(ns[i])){
                        m=m*10+int(ns[i]-'0');
                        i++;
                    }
                    num.emplace_back(m);
                    i--;
                }
                else if(ns[i]=='+'||ns[i]=='-'){
                    //将栈内能算的先算，避免之后算让如（-+）操作的+号运算比-前
                    int t1,t2,tmp;
                    while(!op.empty()&&op.back()!='('){
                        t1=num.back();
                        num.pop_back();
                        t2=num.back();
                        num.pop_back();
                        char o=op.back();
                        op.pop_back();
                        if(o=='+')
                            tmp=t2+t1;
                        else if(o=='-')
                            tmp=t2-t1;
                        num.emplace_back(tmp);
                    }
                    op.emplace_back(ns[i]);
                }

                else if(ns[i]==')'){
                    int t1,t2,tmp;
                    while(op.back()!='('){
                        t1=num.back();
                        num.pop_back();
                        t2=num.back();
                        num.pop_back();
                        char o=op.back();
                        op.pop_back();
                        if(o=='+')
                            tmp=t2+t1;
                        else if(o=='-')
                            tmp=t2-t1;
                        num.emplace_back(tmp);
                    }
                    op.pop_back();
                }
            }
        }
        int t1,t2,tmp;
        while(!op.empty()){
            char o=op.back();
            op.pop_back();
             t1=num.back();
            num.pop_back();
             t2=num.back();
            num.pop_back();
            if(o=='+')
                tmp=t2+t1;
            else if(o=='-')
                tmp=t2-t1;
            num.emplace_back(tmp);
        }
        return num.back();
    }
};


#endif //LEETCODE_SOLUTION66_H