-
Notifications
You must be signed in to change notification settings - Fork 0
/
evaluator.cpp
171 lines (142 loc) · 4.57 KB
/
evaluator.cpp
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
#include "evaluator.h"
using namespace std;
Evaluator::Evaluator(string input){
this->input = input;
this->qu = new Queue(input.length());
this->st = new Stack(input.length());
}
Evaluator::Evaluator(const Evaluator& another){
this->input = another.input;
this->qu = new Queue(input.length());
this->st = new Stack(input.length());
for(int i = 0; i< this->qu->getSize(); i++){
this->qu[i] = another.qu[i];
}
for(int i = 0; i< this->st->getSize(); i++){
this->st[i] = another.st[i];
}
}
Evaluator::~Evaluator(){
delete qu;
delete st;
}
void Evaluator::toPostfix(){
_prepareInput();
for (size_t i = 0; i < input.length(); ++i) {
string current;
// Check if the character is a digit
if (isdigit(input[i])) {
if(input[i-1] == 'u') current += "-"; // unary minus
// If it's a number with more than 1 digit
while (i < input.length() && (isdigit(input[i]))) {
current += input[i];
++i;
}
//for the non-digit character in the next iteration
--i;
}
else if(input[i]=='u') continue; //skipping unary minus to reunite it later
else current = input[i];
_decideAndPut(current);
}
while(! st->isEmpty()){
if(st->peek() != "(" && st->peek() != ")"){
qu->enqueue(st->pop());
}
else{
st->pop();
}
}
}
void Evaluator::_prepareInput(){
string newinput;
if(input.find(' ')!= string::npos){ // delete Spaces
stringstream ss(this->input);
string temp;
while(ss >> temp) newinput+= temp;
} else newinput = this->input;
for(int i = 0; i < newinput.length(); i++){
if (newinput[i] == '-'){
if( (i == 0) || (!isdigit(newinput[i-1])) && newinput[i-1]!= ')'){
newinput.replace(i, 1, "u"); // replacing unary minus heh
}
}
}
this->input = newinput;
};
void Evaluator:: _decideAndPut(const string& value){
if (_ifNumber(value)){
qu->enqueue(value);
}
else{
Operator op(value);
while( !st->isEmpty() && st->peek() != "(" ){
Operator last(st->peek());
bool action = ( last.getPrec() > op.getPrec()
|| (last.getPrec() == op.getPrec() && op.isLeft() ) );
// if equal and left assotiative
if (!action) break;
if(st->peek() != "(" && st->peek() != ")"){
qu->enqueue(st->pop());
}
}
if (value == ")") {
if(st->peek() == ")") st->pop();
if(st->peek() == "(") st->pop();
}
else st->push(value);
}
}
bool Evaluator::_ifNumber(const string& s){
string operators = "+-/*%()^";
if (operators.find(s) == string::npos){
return true;
}
else if (s.length() > 1 && s[0] == '-') return true;
else return false;
}
int Evaluator::PostfixEval(){
while(!qu->isEmpty()){
string token = qu->dequeue();
if(_ifNumber(token)){
st->push(token);
}
else st->push(_countRes(token));
}
return stoi(st->pop());
}
string Evaluator::_countRes(string& token){
int b = stoi(st->pop());
int a = stoi(st->pop());
if (token == "+") return to_string(a+b);
if (token == "-") return to_string(a-b);
if (token == "*") return to_string(a*b);
if (token == "/") return to_string(a/b);
if (token == "%") return to_string(a%b);
if (token == "^") return to_string(pow(a, b));
throw invalid_argument("(Parser::_countRes) Unable to calculate with operand "
+ token);
}
const string Operator::operator_list = "+-*/%^()";
string Operator::value(){ return o; };
Operator::Operator(string value){
if (operator_list.find(value) == string::npos){
throw invalid_argument("Operator " + value+ " cannot be created," +
"as it is probably not an operator. Accepting operator: " + operator_list);
}
this->o = value;
this->precedence = -1;
this->left = (value != "^");
}
void Operator::countPrec(){
if (o == ")") this->precedence = 0;
if (o == "+" || o == "-") this->precedence = 1;
if (o == "*" || o == "/" || o == "% ") this->precedence = 2;
if (o == "^") this->precedence = 3;
if (o == "(") this->precedence = 4;
}
int Operator::getPrec(){
if (precedence == -1) countPrec();
return this->precedence;
}
bool Operator::isLeft(){ return left; }