Valid parenthesis
topic
Given a string containing only '(', ')', '{', '}', '[', ']', determine whether the string is valid.
A valid string needs to be satisfied: the
left bracket must be closed with the same type of right bracket.
The left bracket must be closed in the correct order.
Note that an empty string can be considered a valid string.
Example 1:
Input: "()"
Output: true
Example 2:
Input: "() [] {}"
Output: true
Example 3:
Input: "(]"
Output: false
Example 4:
Input: "([]]"
Output: false
Example 5:
Input: "{[]}"
Output: true
Run the code
class Solution {
public:
bool isValid(string s) {
stack<char> st;
st.push('#');
char c[150];
c['('] = ')';
c['{'] = '}';
c['['] = ']';
if(s.empty())
return true;
for(auto ch : s) {
if (ch == '(' || ch == '{' || ch == '[')
st.push(ch);
else if (c[st.top()] == ch)
st.pop();
else
return false;
}
if(st.top() == '#')
return true;
return false;
}
};
operation result
