CF159D.Palindrome pairs
普及/提高-
通过率:0%
AC君温馨提醒
该题目为【codeforces】题库的题目,您提交的代码将被提交至codeforces进行远程评测,并由ACGO抓取测评结果后进行展示。由于远程测评的测评机由其他平台提供,我们无法保证该服务的稳定性,若提交后无反应,请等待一段时间后再进行重试。
题目描述
You are given a non-empty string s consisting of lowercase letters. Find the number of pairs of non-overlapping palindromic substrings of this string.
In a more formal way, you have to find the quantity of tuples (a,b,x,y) such that 1<=a<=b<x<=y<=|s| and substrings s[a... b] , s[x... y] are palindromes.
A palindrome is a string that can be read the same way from left to right and from right to left. For example, "abacaba", "z", "abba" are palindromes.
A substring s[i... j] ( 1<=i<=j<=∣s∣ ) of string s = s1s2... s∣s∣ is a string sisi+1... sj . For example, substring s[2...4] of string s = "abacaba" equals "bac".
输入格式
The first line of input contains a non-empty string s which consists of lowercase letters ('a'...'z'), s contains at most 2000 characters.
输出格式
Output a single number — the quantity of pairs of non-overlapping palindromic substrings of s .
Please do not use the %lld format specifier to read or write 64-bit integers in С++. It is preferred to use cin, cout streams or the %I64d format specifier.
输入输出样例
输入#1
aa
输出#1
1
输入#2
aaa
输出#2
5
输入#3
abacaba
输出#3
36