二叉树 小球下落问题

#include <stdio.h>
#include <string.h>
#define MAXD 20
int state[1<<MAXD];
int main()
{
int D, I;
while(scanf("%d%d", &D, &I) == 2)
{
int i, k, n = (1<<D)-1;
memset(state, 0, sizeof(state));
for(i = 0; i < I; i++)
{
for(k = 1;;)
{
state[k] = !state[k];
k = state[k] ? (2*k) : (2*k+1);
if(k > n)    break;
}
}
printf("%d\n", k/2);
}
return 0;
}

#include <stdio.h>
int main()
{
int D, I;
while(scanf("%d%d", &D, &I) == 2)
{
int i, k = 1;
for(i = 0; i < D - 1; i++)
{
if(I % 2 == 1)
{
k = k * 2;
I = (I + 1)/2; //左子树比右子树多落一个
}
else
{
k = k * 2 + 1;
I = I / 2;
}
}
printf("%d\n", k);
}
return 0;
}