LeetCode/C++/20-Valid-Parentheses.cpp at master · Sixzeroo/LeetCode · GitHub

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
class Solution {
public:
    bool isValid(string s) {
        stack<char> st;
        for(int i=0;i<s.size();i++)
        {
            switch(s[i])
            {
                case '(':
                    st.push('(');
                    break;
                case ')':
                    if(st.empty() || st.top() != '(')
                        return false;
                    else
                        st.pop();
                    break;
                case '[':
                    st.push('[');
                    break;
                case ']':
                    if(st.empty() || st.top() != '[')
                        return false;
                    else
                        st.pop();
                    break;
                case '{':
                    st.push('{');
                    break;
                case '}':
                    if(st.empty() || st.top() != '{')
                        return false;
                    else
                        st.pop();
                    break;
            }
        }
        if(st.empty())
            return true;
        else
            return false;
    }
};