CareerCup

I have the following algo: please let me know if there are any faults in it..

Case I: The given number is a palindrome..eg: 1234321
then simply increment the center digit by 1 i.e the ans is 1235321

CaseII: The given number is not a palindrome:
Subcase 1: The number to the left of the middle digit is greater than the number on the right eg:2194135 (here 219 > 135)
reverse the left side numbers and replace the right side numbers with them, therefore the ans will be 2194912
Subcase 2:The number to the right of the middle digit is greater than the number on the left eg:1354219
then increment the middle digit by 1 and then reverse the left side numbers and replace the right side numbers with them.. therefore the answer would be 135 5(middle digit incremented) 531(reversed).1355531.

Note: in case the middle digit is 9 then incrementing it would make it 10..so put 0 instead of 9 and increment the first right and left neighboring digit of 9 by 1.

//#include<conio.h>
#include<stdio.h>
void main()
{
int x,y,z;
printf("plz enter the number.");
scanf("%d",&x);
if(check(++x))
print("%d",x);
getch();
}
int check(int i)
{ int j,k;
i=j;
while(j<10)
{
k=j%10;
k=k*10;
j=j/10;
k=k+j;
}
if(i==k)
return 1;
else return 0;
}

Can someone explain the algo?

#include<stdio.h>
#include<string.h>
int main()
{
	char a[1000001];
	int n;
	scanf("%d", &n);
	while(scanf("%s", a)!=EOF)
	{
		int len = strlen(a), l, r, center;
		if(len%2 == 0)
			{l = len/2-1; r = len/2;}
		else
			{l = r = len/2;}
		center = l;
		while(l>=0 && r<len)
		{
			if(a[l] != a[r])
				break;
			l--; r++;
		}
		if(l<0 || a[l]<a[r])
		{
			l = center;
			int carry = 1;
			do{
				a[l] += carry;
				if(a[l] == '9'+1)
					a[l] = '0';
				else
					{carry = 0;break;}
				l--;
			}while(carry==1 & l>=0);
			if(l<0)
			{
				int i;
				for(i=0;i<len-1;i++)
					a[i] = '0';
				a[len-1] = '1';
				printf("1%s\n", a);
				continue;
			}
		}
		if(len%2 == 0)
			{l = len/2-1; r = len/2;}
		else
			{l = r = len/2;}
		while(l>=0 && r<len)
		{
			a[r++] = a[l--];
		}
		printf("%s\n", a);

	}
}

//I know it is not concise, but it works.. the algorithm is simple

#include <iostream>
using namespace std;

int main()
{
int val = 57811;
int count =0;
int a[10];
int b[10];
int mode = val;
int div = 0;
//int temp = val;
int mid = 0;


while(mode)
{
mode = mode/10;
count++;
}

mode = val;
for(int i = 0; i<count; i++)
{
div = mode%10;
mode = mode/10;
a[count-1-i]=div;
//cout<<" " <<a[i];
}

if((count%2)!= 0)
mid = count/2 +1;
else
mid = count/2 ;

for(int j=0;j<mid;j++)
{
if(a[j] == a[count-1-j])
{
b[count-1-j] = a[j];
b[j] = a[j];
}
else if(a[j]>a[count-1-j])
{
b[count-1-j] = a[j];
b[j] = a[j];
}
else
{
if(j == mid -1)
b[j] = b[count-1-j] = a[j]+1;
else{
a[j+1] = a[j+1]+1;
b[j+1] = a[j+1];
b[count-j-2]=a[j+1];
a[count-j-2] = a[j+1];
b[j] = a[j];
b[count-1-j] = a[j];
}
}
}


for(int k=0;k<count;k++)
cout<<" " <<b[k];



return 0;
}

if number is 121,its next smallest would be 131
if number is 12321, its next smallest would be 12421
So if you observe you just need to increment the middle element by 1. Simple!