题解 | #跳台阶#

public class Solution {
    public int jumpFloor(int target) {
        // int []dp = new int[target + 1];
        //由于dp[2] = 2 且dp[1] = 1 则设dp[0]=1
        //dp[0] = 1;
        //dp[1] = 1;

        //优化： 每次dp的运算都只需要前两个dp
        if(target <= 1 ) return 1;
        int a = 1;
        int b = 1;
        int temp = 0;
        for (int i = 2 ; i <= target ; i++) {
            // dp[i] = dp[i - 1] + dp[i - 2];
            temp = a + b;
            a = b;
            b = temp;
        }
        // return dp[target];
        return temp;
    }
}