题解 | #斐波那契数列#

public class Solution {
    public int Fibonacci(int n) {
        if(n == 1 || n == 2){
            return 1;
        }
        int a = 1;
        int b = 1;
        int sum = 0;
        for(int i = 3; i <= n; i++){
            sum = a + b;
            a = b;
            b = sum;
        }
        return sum;
    }
}