青蛙跳台阶（斐波那契数列）

			class Solution {
			public:
				int jumpFloor(int number) {
					if (number <= 0)
					{
						return 0;
					}
					if (number == 1)
					{
						return 1;
					}
					if (number == 2)
					{
						return 2;
					}
					int first = 1, second = 2, third;
					*--------重点-------------
					for (int i = 3; i <= number; i++)
					{
						third = first + second;
						first = second;
						second = third;

					}
					*--------重点-------------
					return third;
				}
			};