palindrome in cpp code example
Example 1: check if a string is palindrome cpp
#include <bits/stdc++.h>
using namespace std;
int main(){
string s;
cin >> s;
int l = 0;
int h = s.length()-1;
while(h > l){
if(s[l++] != s[h--]){
cout << "Not a palindrome" << endl;
return 0;
}
}
cout << "Is a palindrome" << endl;
return 0;
}
Example 2: next palindrome number in cpp
#include <iostream>
bool isPalindrome (int number) {
int decomposed = number, reversed = 0;
while (decomposed) {
reversed = 10 * reversed + (decomposed % 10);
decomposed /= 10;
}
return reversed == number;
}
int nextPalindromicNumber (int number) {
while (!isPalindrome(++number));
return number;
}
int main () {
int testCases;
std::cin >> testCases;
while (testCases--) {
int number;
std::cin >> number;
std::cout << nextPalindromicNumber(number) << '\n';
}
}
Example 3: palindrome c++
#include<iostream>
#include<string>
#include<algorithm>
bool IsPalindrome_true_false(const std::string& );
int main ()
{
std::cout<<"Please enter a string:\t";
std::string str;
getline(std::cin, str);
int i = 0;
while(str[i])
{
if(str[i] == std::toupper(str[i]) && std::isalpha(str[i]) == 1024)
str[i]+= 32;
++i;
}
while(str.empty())
{
std::cout<<"\nPlease enter a string your string is empty:\t";
if(!str.empty())
std::string str;
getline(std::cin, str);
}
std::cout<<"\n"<<std::boolalpha<<IsPalindrome_true_false(str)<<std::endl;
std::cout<<std::endl;
return 0;
}
bool IsPalindrome_true_false(const std::string& str)
{
int i = 0;
int j = str.length() - 1;
while(i <= j )
{
if(std::isalpha(str[i]) == 0){
++i;
continue;
}else if(std::isalpha(str[j]) == 0){
--j;
continue;
}
if(str[i] != str[j]){
return false;
}
++i;
--j;
}
return true;
}
Example 4: next palindrome number in cpp
#include <iostream>
#include <string.h>
using namespace std;
int nextpalin (int num){
while (num++) {
string str = to_string (num);
int l = str.length()-1;
int s = 0;
while( s<l ){
if (str[s]!=str[l]) break;
else {
s++;
l--;
}
if (s>=l) return num;}
}
}
int main () {
int t;
cin >> t;
while (t--){
int num;
cin >> num;
if (num==0) cout << "1" << endl;
else {
if (num<9) cout << num+1 << endl;
else cout << nextpalin( num) << endl;}
}
}