题目
输入只包含’(‘, ‘)’, ‘{‘, ‘}’, ‘[‘ , ‘]’的字符串，判断字符串是否合法，”()” and “()[]{}”是合法的，”(]” and “([)]”是非合法的
分析
显然是使用栈进行实现
C++代码实现
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class Solution {
public:
bool isValid(string s) {
stack<char> tmp;
tmp.push('0');
for(int i = 0; i < s.size(); i ++)
{
if(abs(tmp.top() - s[i]) < 5 && tmp.top() != s[i])
tmp.pop();
else tmp.push(s[i]);
}
return tmp.size() == 1;
}
};
*/
class Solution {
public:
bool (string s) {
stack<char> tmp;
for(int i = 0; i < s.size(); i ++)
{
if(s[i] == '[' || s[i] == '(' || s[i] == '{')
tmp.push(s[i]);
else{
if(tmp.empty()) return false;
else{
if(abs(tmp.top() - s[i]) < 5)
tmp.pop();
else return false;
}
}
}
if(tmp.empty()) return true;
else return false;
}
};
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Python代码实现
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class Solution(object):
def (self, s):
"""
:type s: str
:rtype: bool
"""
stack = ['0']
for i in s:
if i!=stack[-1] and abs(ord(i)-ord(stack[-1]))<5:
stack.pop()
else:
stack.append(i)
return stack==['0']
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