C++程序：查找具有相同左右旋转的最长子序列

#include <iostream>
#include <string>
using namespace std;

// Defining global variable to store the length of the longest subsequence according to the given condition
int maxLen = 0;
//  function to check if the string is the same after the left rotation
bool isRightSameLeft(string str) {
   int len = str.length();
   return str.substr(1, len - 1) + str[0] == str[len - 1] + str.substr(0, len - 1);
}
// function to get all subsequences of a string
void getAllSubSeqs(string str, string out) {
   // If the string is empty, we get the subsequences. Check if its left and right rotation is the same
   if (str.empty()) {
      if (isRightSameLeft(out))
          maxLen = max(maxLen, (int)out.length());
      return;
   }
   // Recursive case remove the first character from str, and add it to the output
   getAllSubSeqs(str.substr(1), out + str[0]);
   // remove the first character from str, and drop it
   if (str.length() > 1)
      getAllSubSeqs(str.substr(1), out);
}
int main() {
   string str = "323232";
   string out = "";
   getAllSubSeqs(str, out);
   cout << "The longest subsequence of str having same left and right rotation is " << maxLen;
   return 0;
}

#include <bits/stdc++.h>
using namespace std;

int getLongSubSeq(string str) {
   // Store the length of the string
   int len = str.size(), res = 0;
   // Traverse the all possible combination of two digits
   for (int i = 0; i < 10; i++) {
      for (int j = 0; j < 10; j++) {
          // to store the length of an alternating sequence of the current combination
          int cnt = 0;
          // to track the turn of the ith or jth digit
          bool first = true;
          // traverse the string
          for (int k = 0; k < len; k++) {
              // If the current digit is equal to I, and the first is true, increment the count
              if (first == true and str[k] - '0' == i) {
                  first = false;
                  cnt++;
              } else if (first == false and str[k] - '0' == j) {
                  // If the current digit is equal to j, and the first is false, increment the count
                  first = true;
                  cnt++;
              }
          }
          // If the sequence is odd and i and j are different, decrement the count
          if (i != j and cnt % 2 == 1)
              cnt--;
          // Update the answer
          res = max(cnt, res);
       }
   }
   return res;
}
int main() {
   string str = "00010100";
   cout << "The longest subsequence of str having same left and right rotation is " << getLongSubSeq(str);
   return 0;
}