08. Jump the stairs

topic

A frog can jump up to 1 step at a time, or jump up to 2 steps. Find the total number of jumping methods for the frog to jump on an n-level step (different order to calculate different results).

Code

public class Solution {
	//动态规划的简单应用及斐波那契数列变体
    public int JumpFloor(int target) {
        if(target <= 2){
            return target;
        }
        int first = 1;
        int second = 2;
        int temp = 0;
        for(int i = 3; i <= target; i++ ){
            temp = first + second;
            first = second;
            second = temp;
        }
        return temp;
    }
}