Query code: 4_7_4.c

#include <stdio.h>
#include <string.h>

int palidrome(char* num);

int main(int argc, char* argv[])
{
    int i, j, max = 0;
    char num[8];
    
    for(i = 999; i > 0; i--) { for(j = i; (i*j) > max; j--)
    {
        sprintf(num, "%i", i*j);
        if(palidrome(num)) max = i*j;
    }}
    
    return max;
}

int palidrome(char* num)
{
    int i, len = strlen(num);
    for(i = 0; i < (len / 2); i++) if(num[i] != num[len - i - 1]) return 0;
    return 1;
}
Results:

63_4_12.c
36_5_2.c
4_5_13.c
4_1_10.c
27_6_12.c
4_4_8.c
23_5_8.c
4_7_14.c
58_4_6.c
58_8_18.c