机试第2章

反序数

int reverse(int x)
{
    int res = 0;
    while (x)
    {
        res *= 10;
        res += x % 10;
        x /= 10;
    }
    return res;
}

闰年判断

int d1[13] = {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
int d2[13] = {0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};

bool isLeapYear(int n)
{
    return (n % 4 == 0 && n % 100 != 0) || (n % 400 == 0);
}

日期格式化输出yyyy-mm-dd

printf("%04d-%02d-%02d", y, m, d);