HINTS (use them carefully!)
:::info[Hint 1]
Generate the palindromes and see if they are prime.
:::
:::info[Hint 2]
Generate palindromes by combining digits properly. You might need more than one of the loops like below.
/* generate five digit palindrome: */
for (d1 = 1; d1 <= 9; d1+=2) { /* only odd; evens aren't so prime */
for (d2 = 0; d2 <= 9; d2++) {
for (d3 = 0; d3 <= 9; d3++) {
palindrome = 10000*d1 + 1000*d2 + 100*d3 + 10*d2 + d1;
/* ... deal with palindrome ... */
}
}
}
:::
USACO Training Section 1.5
