验证回文数,本来挺简单的一道题,开始想玩一下栈结构,结果爆内存了
下附爆内存代码:
class Solution {
public:
bool isPalindrome(string s) {
string LTR,RTL;
stack<char> sk;
int i,n=s.size();
if(s=="")
return true;
for(i=0;i<n;i++)
{
if(s[i]>='a' && s[i]<='z' || s[i]>='0' && s[i]<='9')
{
sk.push(s[i]);
LTR=LTR+s[i];
}
else if(s[i]>='A' && s[i]<='Z')
{
sk.push(char(s[i]+32));
LTR=LTR+char(s[i]+32);
}
}
while(!sk.empty())
{
RTL=RTL+sk.top();
sk.pop();
}
return (LTR==RTL);
}
};
还是乖乖用最老土的方式解决吧……
class Solution {
public:
bool isPalindrome(string s) {
int low=0,high=s.size()-1;
while(low<high)
{
if(!(s[low]>='A' && s[low]<='Z' || s[low]>='a' && s[low]<='z' || s[low]>='0' && s[low]<='9')){low++;continue;}
if(!(s[high]>='A' && s[high]<='Z' || s[high]>='a' && s[high]<='z' || s[high]>='0' && s[high]<='9')){high--;continue;}
if((s[low]>='a' && s[low]<='z') && (s[low]!=s[high] && char(s[low]-32)!=s[high])) return false;
else if((s[low]>='A' && s[low]<='Z') && (s[low]!=s[high] && char(s[low]+32)!=s[high])) return false;
else if((s[low]>='0' && s[low]<='9') && (s[low]!=s[high])) return false;
low++;
high--;
}
return true;
}
};