3AC-C++

#include <bits/stdc++.h>
using namespace std;

map <char,int> precedence;

bool sortbysec(const pair<char,int> &a,
              const pair<char,int> &b)
{
    return (precedence[a.first] < precedence[b.first]);
}

int main()
{
	precedence['/'] = 1;
	precedence['*'] = 2;
	precedence['+'] = 3;
	precedence['-'] = 4;
	int opc = 0;
	char token;
	vector<bool> processed;
	vector<pair<char,int>> ops;
	string inp = "",expr = "", temp;

	cout << "Enter an expression: ";
	getline(cin,inp);

	for(int i = 0;i<inp.length();i++)
	{
		if(inp[i] != ' ')
		{
			expr += inp[i];
		}
	}

	for(int i = 0;i<expr.length();i++)
	{
		processed.push_back(false);
	}

	for(int i = 0;i<expr.length();i++)
	{
		char tk = expr[i];
		if(precedence[tk] != 0)
		{
			ops.push_back(make_pair(tk,i));
			opc++;
		}
	}
	cout << "----------------------------Operators-----------------------" << endl << endl;
	cout << "Operators\tLocation" << endl << endl;

	for(int i = 0;i<opc;i++)
	{
		cout << ops[i].first << "\t\t" << ops[i].second << endl;
	}
	cout << endl << endl <<endl;

	sort(ops.begin(), ops.end(), sortbysec);

	int tmp;
	for(int i = 0;i<opc;i++)
	{
		tmp = ops[i].second;
		string op1 = "", op2 = "";
		if(processed[tmp-1] == true)
		{
			if(precedence[ops[i-1].first] == precedence[ops[i].first])
			{
				op1 = "t" + i;
			}
			else
			{
				for(int k = 0;k<opc;k++)
				{
					if(tmp-2 == ops[k].second)
					{
						char c = k+1 + '0';
						op1 = "t";
						op1 += c;
					}
				}
			}
		}
		else
		{
			op1 = expr[tmp-1];
		}
		if(processed[tmp+1] == true)
		{
			for(int k = 0;k<opc;k++)
			{
				if(tmp+2 == ops[k].second)
				{
					char c = k+1 + '0';
					op2 = "t";
					op2 += c;
				}
			}
		}
		else
		{
			op2 = expr[tmp+1];
		}
		cout << "t" << i+1 << " = " << op1 << " " << ops[i].first << " " << op2 << endl;
		processed[tmp] = true;
		processed[tmp-1] = true;
		processed[tmp+1] = true;
	}
	cout << endl;

	//cout << expr;
}