-
Notifications
You must be signed in to change notification settings - Fork 1
/
Copy path227.cpp
118 lines (104 loc) · 1.88 KB
/
227.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
#include <iostream>
#include <string>
#include <stack>
using namespace std;
class Solution {
public:
int prio(char c) {
int p = 1;
if (c == '*' || c == '/') p++;
return p;
}
int getresult(int a, int b, char op) {
int res = a;
if (op == '+') {
res = res + b;
}
else if (op == '-') {
res = res - b;
}
else if (op == '*') {
res = res * b;
}
else if (op == '/') {
res = res / b;
}
return res;
}
int calculate(string s) {
stack<int> opr;
stack<char> op;
while (!opr.empty()) {
opr.pop();
}
while (!op.empty()) {
op.pop();
}
int x = 0;
char c;
for (int i = 0; i < s.length(); i++) {
c = s[i];
if (c >= '0' && c <= '9') {
x = x * 10 + c - 48;
}
else if (c == '+' || c == '-' || c == '*' || c == '/'){ // + - * /
opr.push(x);
x = 0;
while (!op.empty() && !(prio(c) > prio(op.top()))) {
int a, b;
int res;
if (!opr.empty()) {
b = opr.top();
opr.pop();
}
else {
return -1;
}
if (!opr.empty()) {
a = opr.top();
opr.pop();
}
else {
return -1;
}
res = getresult(a, b, op.top());
op.pop();
opr.push(res);
}
op.push(c);
}
}
opr.push(x);
while (!op.empty()) {
int a, b;
int res;
if (!opr.empty()) {
b = opr.top();
opr.pop();
}
else {
return -1;
}
if (!opr.empty()) {
a = opr.top();
opr.pop();
}
else {
return -1;
}
res = getresult(a, b, op.top());
op.pop();
opr.push(res);
}
return opr.top();
}
};
int main() {
Solution test;
cout << test.calculate("3+2*2") << endl;
cout << test.calculate("3+5/2") << endl;
cout << test.calculate("3/2*2") << endl;
cout << test.calculate("3-5/2") << endl;
system("pause");
return 0;
}