Need some help while implementing RPN

[Thank You]

I tried to implement this algorithm on c++. I tried almost 8 hrs. 2 hrs for understanding algorithm ,that it is very hard . But that was easy. And almost roughly 6 hours of coding.
I want to implement this in plain C++. And can use deque and vector
And this is not my homework or any task!!! I am just trying to learn something extra since I don't have machine to run higher stuff like QT

I haven't visited any implementation before this of the same thing. I tried to implement it on JavaScript at first and I completed it but couldn't complete this in c++

If you are free then try compiling this

some cout are just for debugging purpose and try catch blocks are also for the same. I got tired of seeing this thing so posting here

ALSO rate my coding style out of 10
LOL

#include <iostream>
#include<vector>
#include <string>
#include <string.h>
#include<algorithm>
#include<cmath>
#include<map>
#include<deque>

using  std::cout,std::cin, std::string, std::endl;
// THIS MUST BE COMPILED WITH C++17, Because comma separated value are supported with it
// g++ main.cpp -std=c++17

#define LEFT_TO_RIGHT  "LEFT_TO_RIGHT"
#define RIGHT_TO_LEFT  "RIGHT_TO_LEFT"
// can use const too

std::map<string,int> precedenceDeclaration;
std::map<string,string> associativeDeclaration;

void fillFirst(){
	//
	precedenceDeclaration.insert(std::make_pair("(",0));
	precedenceDeclaration.insert(std::make_pair("[",0));
	precedenceDeclaration.insert(std::make_pair("{",0));
	precedenceDeclaration.insert(std::make_pair("+",1));
	precedenceDeclaration.insert(std::make_pair("-",1));
	precedenceDeclaration.insert(std::make_pair("/",2));
	precedenceDeclaration.insert(std::make_pair("*",2));
	precedenceDeclaration.insert(std::make_pair("%",2));
	precedenceDeclaration.insert(std::make_pair("^",3));
	precedenceDeclaration.insert(std::make_pair(")",4));
	precedenceDeclaration.insert(std::make_pair("}",4));
	precedenceDeclaration.insert(std::make_pair("]",4));

	associativeDeclaration.insert(std::make_pair("+",LEFT_TO_RIGHT));
	associativeDeclaration.insert(std::make_pair("-",LEFT_TO_RIGHT));
	associativeDeclaration.insert(std::make_pair("*",LEFT_TO_RIGHT));
	associativeDeclaration.insert(std::make_pair("/",LEFT_TO_RIGHT));
	associativeDeclaration.insert(std::make_pair("%",LEFT_TO_RIGHT));
	associativeDeclaration.insert(std::make_pair("^",RIGHT_TO_LEFT));

}
int precedence(string op){
	if(precedenceDeclaration.count(op) < 1){
		throw "character is invalid for precedence";
	}
	return precedenceDeclaration[op];
}
std::string associativity(string toFind){
	if(associativeDeclaration.count(toFind) < 1){
		throw "Character is invalid for associativity";
	}
	return associativeDeclaration[toFind];
}
bool isNumber(string value){
	for(auto v : value){
		if(std::isdigit(v) == false){
			return false;
		}
	}
	return true;
}
std::string last(std::deque<string> arr){
	if(arr.size() == 0 ){
		throw "Cannot get the last element of empty structure";
		// throw 10;
	}

	return arr.at(arr.size() - 1);
}
bool isValidCharacter(string value){
	try{
		if(precedence(value) >= 0){
			return true;
		}
	}catch(string err){
		std::cout<<err;
		std::cout<<"The character is not valid character!!!!!!!!!!";
	}

	return false;
}
bool isValidOperator(string value){
	try{
		if(precedence(value) > 0 && precedence(value) < 4){
			return true;
		}
	}catch(string err){
		std::cout<<err;
		std::cout<<"The character is not valid operator!!!!!1";
	}

	return false;
}
float convertToNumber(string str){
	return atof(str.c_str());
}
string convertToStringS(char s){
	return string({s});
}
float evaluateOperation(string op1 , char operatorInput, string op2){
	float operand1 = convertToNumber(op1);
	float operand2 = convertToNumber(op2);

	switch(operatorInput){
		case '+':
		 return operand1 + operand2;
		 break;
		case '-':
			return operand1 - operand2;
		break;
	}

	return 500;
}
template <typename Data> void display(Data val){
	std::cout<<"\n{ ";
	for(auto v:val){
		std::cout<<" '"<<v<<"',";
	}
	std::cout<<" }";
}

void RPN(string equation);


int main(){

	fillFirst();
	string operation = "3 + 4 * 2 / ( 1 - 5 ) ^ 2 ^ 3";
	RPN(operation);
}
/*
[
  '3', '4', '2', '*',
  '+', '1', '5', '-',
  '2', '3', '^', '^',
  '/'
]

*/


void RPN(string equation){
	std::deque<std::string> stack,output;


	for(auto eq:equation){
		string currentCharacter = convertToStringS(eq);
		if(currentCharacter == " " || currentCharacter == "."){
			continue;
		}

		if(isNumber(currentCharacter)){
			output.push_back(currentCharacter);
		}else if(isValidCharacter(currentCharacter)){
			std::cout<<"\nOperator = "<<currentCharacter<<std::endl;
			int currentPrecedence = precedence(currentCharacter);

			if(currentPrecedence == 0  ){
				output.push_back(currentCharacter);
			}else if(currentPrecedence == 4){
				
				while(precedence(last(stack)) != 0){
					string lastStack = last(stack);
					stack.pop_back();
					output.push_back(lastStack);
					if(stack.size() == 0 ){
						break;
					}
				}				
				if(stack.size() != 0){stack.pop_back(); display(stack);}
			}

			auto performBack = [&](){
				if(stack.size() != 0){
				while(currentPrecedence < precedence(last(stack))){
				std::cout<<"inside performBack "<<std::endl;
				display(stack);
				display(output);
					if(stack.size() == 0 )
						break;

					string lastWord = last(stack);
					output.push_back(lastWord);
					stack.pop_back();
				}
			}
				stack.push_back(currentCharacter);
			};

/////////////////////////////////////////////////////////////////////////////////////////////////////////
		THAT THROW IS JUST FOR CHECKING!!!!!!!!!!!!!!!!
			if(isValidOperator(currentCharacter)){
				if(stack.size() == 0 ){
					stack.push_back(currentCharacter);
				}else if(currentPrecedence > precedence(last(stack)) || precedence(last(stack)) == 0){
					stack.push_back(currentCharacter);
				}else if(currentPrecedence < precedence(last(stack))){
					performBack();
					/*
					while(stack.size() != 0 || currentPrecedence > precedence(last(stack))){
						string lastWord = last(stack);
						output.push_back(lastWord);
						stack.pop_back();
					}
					*/
				}else if(currentPrecedence == precedence(last(stack))){
					
					if(associativity(currentCharacter) == LEFT_TO_RIGHT){
						performBack();
					}else if(associativity(currentCharacter) == RIGHT_TO_LEFT){
						stack.push_back(currentCharacter);
					}
					
				}
			}

		}

	display(output);
	display(stack);
	}
}

[Thank You]

Hello guys
@jsulm @mrjj @JonB @SGaist @AnneRanch
I hope to get some thoughts on this!