USACO section1.2 Dual Palindromes

给出 n 和 s （十进制），打印 s 后面 n 个在 2-10 进制中至少两个进制下为回文数的十进制表示。

/*
PROG: dualpal
LANG: C++
*/
# include <cstdio>
# include <cstring>

int n, s;

void strRev(char *s)
{
    char ch;
    int len = strlen(s), mid = len / 2;
    for (int i = 0; i < mid; ++i)
        ch = s[i], s[i] = s[len-1-i], s[len-1-i] = ch;
}

void to(int base, int x, char *s)
{
    int i = 0;
    while (x > 0)
    {
        s[i++]  = x % base + '0';
        x /= base;
    }
    s[i] = '\0';
    strRev(s);
}

char isPal(char *s)
{
    int len = strlen(s), mid = len / 2;
    for (int i = 0; i < mid; ++i)
        if (s[i] != s[len-1-i]) return 0;
    return 1;
}

int main()
{
    freopen("dualpal.in", "r", stdin);
    freopen("dualpal.out", "w", stdout);

    scanf("%d%d", &n, &s);
    int cnt = 0;
    char buf[30];
    for (int i = s+1; cnt < n; ++i)
    {
        char ok = 0;
        int c = 0;
        for (int j = 2; j <= 10; ++j)
        {
            to(j, i, buf);
            if (isPal(buf)) ++c;
            if (c >= 2) {ok = 1; break;}
        }
        if (ok) {printf("%d\n", i);++cnt;}
    }

    fclose(stdin);
    fclose(stdout);

    return 0;
}

/**/