UVa 10404 Bachet's Game

乍一看是博弈，也是看了大牛们的思路才会的。。

在确定当前状态时，前面所有的状态都确定了，如果能通过移动一步到达核结点，那么当前局势必胜。

# include <stdio.h>
# include <memory.h>
# include <stdlib.h>

# define INDEX(i) ((i)>>3)
# define OFFSET(i) ((i)&0x7)

# define get_bit(i) ((f[INDEX(i)]>>OFFSET(i)) & 0x1)
# define set_bit(i) (f[INDEX(i)] |= (0x1<<OFFSET(i)))

int s[15];
char f[INDEX(1000000)+10];

int cmp(const void *x, const void *y)
{
    return (*(int*)x < *(int*)y ? -1:1);
}

int main()
{
    int i, j, n, m;

    while (~scanf("%d%d", &n, &m))
    {
        for (i = 1; i <= m; ++i) scanf("%d", &s[i]);

        memset(f, 0, (INDEX(n)+5)*sizeof(char));
        qsort(s+1, m, sizeof(int), cmp);

        for (i = 1; i <= n; ++i)
        for (j = s[1]; j<=m && s[j] <= i; ++j)
            if (!get_bit(i-s[j]))
            {
                set_bit(i);
                break;
            }

        puts(get_bit(n)==1 ? "Stan wins":"Ollie wins");
    }

    return 0;
}