C语言版本实现回文数字

#include <stdio.h>
int main() {
    int n;
    scanf_s("%d", &n);
    int s = 0;
    if (n >= 10 && n <= 100) {
        for (int i = 10001; i <= 999999; ++i) {
            if (i >= 100001) {
                int a = i % 10;
                int f = i / 100000;
                if (a != f) {
                    continue;
                }
                int b = i / 10 % 10;
                int e = i / 10000 % 10;
                if (b != e) {
                    continue;
                }
                int c = i / 1000 % 10;
                int d = i / 100 % 10;
                if (c != d) {
                    continue;
                }
                if ((a << 1) + (b << 1) + (c << 1) == n) {
                    s = 1;
                    printf("%d\n", i);
                }

            }
            else {
                int a = i % 10;
                int e = i / 10000;
                if (a != e) {
                    continue;
                }
                int b = i / 10 % 10;
                int d = i / 1000 % 10;
                if (b != d) {
                    continue;
                }
                int c = i / 100 % 10;
                if ((a << 1) + (b << 1) + c == n) {
                    s = 1;
                    printf("%d\n", i);
                }

            }
        }
    }
    if (!s) {
        printf("%d\n", -1);
    }
    return 0;
}