程序代码：

#include <stdio.h>
#include <time.h>

int foo( int year )
{
    struct tm a = { 0,0,0, 1,11-1,year-1900, 0,0,0 };
    time_t b = mktime( &a );
    if( b == -1 )
        return 0;

    struct tm c = *localtime( &b );
    return (11-c.tm_wday)%7 + 22;
}

int main( void )
{
    printf( "%d\n", foo(2015) ); // 26
    printf( "%d\n", foo(2016) ); // 24
    printf( "%d\n", foo(2017) ); // 23
}