https://leetcode.com/problems/longest-palindromic-substring/
public String longestPalindromeExpandAroundCenter(String s) {
if (s == null || s.length() < 1) return "";
int start = 0, end = 0;
for (int i = 0; i < s.length(); i++) {
int len1 = expandAroundCenter(s, i, i);
int len2 = expandAroundCenter(s, i, i + 1);
int len = Math.max(len1, len2);
if (len > end - start) {
start = i - (len - 1) / 2;
end = i + len / 2;
}
}
return s.substring(start, end + 1);
}
private int expandAroundCenter(String s, int left, int right) {
int L = left, R = right;
while (L >= 0 && R < s.length() && s.charAt(L) == s.charAt(R)) {
L--;
R++;
}
return R - L - 1;
}
System.out.println(新的LongestPalinSubstring().longestpalindromexpandaroundcenter(“cbbd”));
打印:bb
代码将被接受但是当我将java代码转换成javascript代码时,它失败了。
var longestPalindrome = function (s) {
if (s == null || s.length < 1) return "";
var start = 0, end = 0;
for (var i = 0; i < s.length; i++) {
var len1 = expandAroundCenter(s, i, i);
var len2 = expandAroundCenter(s, i, i + 1);
var len = Math.max(len1, len2);
if (len > end - start) {
start = i - (len - 1) / 2;
end = i + len / 2;
}
}
return s.substring(start, end + 1);
};
var expandAroundCenter = function (s, left, right) {
var L = left, R = right;
while (L >= 0 && R < s.length && s[L] == s[R]) {
L--;
R++;
}
return R - L - 1;
}
log(longestpalindrome(“cbbd”))
CBB
为什么JS代码返回“cbb”而不是“bb”?
最佳答案
这与Java的整数除法和Javascript的浮点版本之间的差异有关。
替换为:
if (len > end - start) {
start = i - (len - 1) / 2;
end = i + len / 2;
}
有了这个:
if (len > end - start) {
start = i - Math.floor((len - 1) / 2);
end = i + Math.floor(len / 2);
}
应该会修好的。