C++ algorithm: 1) 10001th prime number 2) Number that divisible fro, 1 to 20 3) Biggest palindromic number for two 3-digit number s product

Program to find palindromic-numbers

给定字符串，求它的回文子序列个数。回文子序列反转字符顺序后仍然与原序列相同。例如字符串aba中，回文子序列为 a , a , aa , b , aba ，共5个。内容相同位置不同的子序列算不同的子序列。-Given a string, find its number of sub-palindromic sequence. Palindromic sequences reversed the order of characters remains the same as the original