青蛙跳台阶的变形,青蛙每次可以跳1、2、。。。n次
public class Solution {
public int JumpFloorII(int target) {
if (target <= 0) {
return -1;
} else if (target == 1) {
return 1;
} else {
return 2 * JumpFloorII(target - 1);
}
}
}