public int JumpFloor(int target) { if(target <= 0) return 0; if(target == 1) return 1; if(target == 2) return 2; int one = 1; int two = 2; int result = 0; for(int i = 2; i < target; i++){
        result = one+ two;
        one = two;
        two = result;
    } return result;
}