leetcode 680. Valid Palindrome II 去除一个字符的回文字符串判断 + 双指针

Given a non-empty string s, you may delete at most one character. Judge whether you can make it a palindrome.

Example 1:

Input: “aba”

Output: True

Example 2:

Input: “abca”

Output: True

Explanation: You could delete the character ‘c’.

Note:

The string will only contain lowercase characters a-z. The maximum length of the string is 50000.

本题题意很简单，要是直接暴力的删除字符会超时，所以直接跳过即可

代码如下：

#include <iostream>
#include <vector>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <string>
#include <climits>
#include <algorithm>
#include <sstream>
#include <functional>
#include <bitset>
#include <numeric>
#include <cmath>
#include <regex>

using namespace std;

class Solution
{
public:
bool validPalindrome(string s)
{
int left = 0, right = s.length() - 1;
while (left < right)
{
if (s[left] == s[right])
{
left++;
right--;
}
else
{
return isPalindrome(s, left, right - 1) || isPalindrome(s, left + 1, right);
}
}
return true;
}

bool isPalindrome(string s,int left,int right)
{
while (left < right)
{
if (s[left] == s[right])
{
left++;
right--;
}
else
return false;
}
return true;
}
};