View difference between Paste ID: DWF6LXCK and G7nzBHEj

 #include <stdio.h>
 #include <math.h>
 #include <time.h>
 #include <windows.h>
 
 typedef time_t prime_t;
 
 prime_t reverseDigits(prime_t num)
 {
     prime_t rev_num = 0;
     while(num > 0)
     {
-        rev_num = rev_num*10 + num%10;
+        rev_num = rev_num * 10 + (num % 10);
-        num = num/10;
+        num = num * 0.1;
     }
     return rev_num;
 }
 
-prime_t nextOddPalindrome(prime_t n) {
+prime_t nextPalindrome(prime_t n) {
     n++;
-        n += 2;
+    int digits = 0;
-    } while(n != reverseDigits(n));
+    prime_t num = n;
     do {
-    return n;
+        digits++;
     } while((num *= 0.1) > 0);
 
     prime_t half = digits * 0.5;
-    int i;
+    prime_t left = n * pow(0.1, half);
     prime_t r_left = reverseDigits(left);
-    if(n < 2)
+    if(r_left % 2 == 0) {
         return nextPalindrome(((int)(n * pow(0.1, digits-1)) + 1) * pow(10, digits-1));
-    else if(n == 2)
+        r_left = reverseDigits(left);
     }
     prime_t p10h  = pow(10, half);
-    for(i = 3; i < sqrt(n) + 1; i+=2)
+    prime_t right = n - (left * p10h);
 
     if(digits % 10) {
         r_left = reverseDigits(left * 0.1);
 
         if(r_left > right)
             return (left * p10h) + r_left;
         else {
             ++left;
             return (left * p10h) + reverseDigits(left * 0.1);
         }
     } else {
         if(r_left > right)
             return (left * p10h) + r_left;
-    if(t % 2 == 0)
+        else {
-        t--;
+            ++left;
             return (left * p10h) + reverseDigits(left);
-        t = nextOddPalindrome(t);
+        }
     }
 }
 
 int isPrime(prime_t n) {
     prime_t i;
 
     if(n == 2)
         return 1;
     else if (n == 3)
         return 1;
     else if (n * 0.5 == 0)
         return 0;
     else if (n % 3 == 0)
         return 0;
 
     i = 5;
     prime_t c = 2;
     while(i * i < n) {
         if(n % i == 0)
             return 0;
         i += c;
         c = 6 - c;
     }
 
     return 1;
 }
 
 int main(int argc, char **argv)
 {
     time_t t = time(NULL);
     printf("next prime palindrome of %I64u is ", t);
 
     unsigned int s = GetTickCount();
 
     do {
         t = nextPalindrome(t);
     } while(!isPrime(t));
 
     printf("%I64u\n", t);
     printf("elapsed %lu milliseconds", GetTickCount() - s);
     return 0;
 }