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;

}

/**/