Valid Parentheses

id20. Valid Parentheses Add to List QuestionEditorial Solution My Submissions
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Difficulty: Easy
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Given a string containing just the characters ‘(‘, ‘)’, ‘{‘, ‘}’, ‘[‘ and ‘]’, determine if the input string is valid.

The brackets must close in the correct order, “()” and “()[]{}” are all valid but “(]” and “([)]” are not.

字符串匹配

class Solution {
public:
    bool isValid(string s) {
        stack<char> st;
        for(int i=0;i<s.length();i++)
        {if(s[i]=='('||s[i]=='['||s[i]=='{')
            st.push(s[i]);
            if(s[i]==')')
            {if(st.empty())
            return 0;
            else{
             if(st.top()=='(')
            st.pop();
            else return 0;
            }
            }
            if(s[i]==']')
            {if(st.empty())
            return 0;
            else{
                if(st.top()=='[')
            st.pop();
            else return 0;
            }}
            if(s[i]=='}')
            {
                if(st.empty())
            return 0;
            else{if(st.top()=='{')
            st.pop();
            else return 0;
            }}
    }
    if(st.empty())
return 1;
else return 0;
}
};