4. int DP_ABString(int count){
int fa[1000], fb[1000];
if(count > 1000) return -1;
memset(fa, 0, sizeof(fa));
memset(fb, 0, sizeof(fb));
for(int i = 1; i < count; i++)
fa[i] = fa[i-1] + fb[i-1];
fb[i] = fb[i-1] + fa[i-1] + i%2; }
return fb[count-1];

10. int DP_Domino(int n) {
int d[1000][3];
if(n%2) return -1;
d[1][0] = d[1][2] = 1;
d[0][0] = d[1][1] = d[0][2] = 1;
for(int i = 2; i <= n; i++)
d[i][0] = d[i-2][0] + d[i-1][1] + d[i-2][2];
d[i][1] = d[i-1][2];
d[i][2] = d[i][0] + d[i-1][1]; }
return d[n][0];