palindrome_no_task.c

#include <stdio.h> 
void printArray (int arr[], int n); 
int AreAll9s (int num[], int n ); 


void generateNextPalindromeUtil (int num[], int n ) 
{ 
	int mid = n/2; 
	bool leftsmaller = false; 

	int i = mid - 1; 
	int j = (n % 2)? mid + 1 : mid; 


	while (i >= 0 && num[i] == num[j]) 
		i--,j++; 

	
	if ( i < 0 || num[i] < num[j]) 
		leftsmaller = true; 

	while (i >= 0) 
	{ 
		num[j] = num[i]; 
		j++; 
		i--; 
	} 

	
	if (leftsmaller == true) 
	{ 
		int carry = 1; 
		i = mid - 1; 

		
		if (n%2 == 1) 
		{ 
			num[mid] += carry; 
			carry = num[mid] / 10; 
			num[mid] %= 10; 
			j = mid + 1; 
		} 
		else
			j = mid; 

		
		while (i >= 0) 
		{ 
			num[i] += carry; 
			carry = num[i] / 10; 
			num[i] %= 10; 
			num[j++] = num[i--]; // copy mirror to right 
		} 
	} 
} 


void generateNextPalindrome( int num[], int n ) 
{ 
	int i; 

	printf("Next palindrome is:"); 

	
	if( AreAll9s( num, n ) ) 
	{ 
		printf( "1 "); 
		for( i = 1; i < n; i++ ) 
			printf( "0 " ); 
		printf( "1" ); 
	} 

	
	else
	{ 
		generateNextPalindromeUtil ( num, n ); 
		printArray (num, n); 
	} 
} 

// function to check if num has all 9s 
int AreAll9s( int* num, int n ) 
{ 
	int i; 
	for( i = 0; i < n; ++i ) 
		if( num[i] != 9 ) 
			return 0; 
	return 1; 
} 

/* prints out an array on a line */
void printArray(int arr[], int n) 
{ 
	int i; 
	for (i=0; i < n; i++) 
		printf("%d ", arr[i]); 
	printf("\n"); 
} 


int main() 
{ 
	int num[] = {9, 4, 1, 8, 7, 9, 7, 8, 3, 2, 2}; 

	int n = sizeof (num)/ sizeof(num[0]); 

	generateNextPalindrome( num, n ); 

	return 0; 
}