public class Solution {
public int climbStairs(int n) {
int[] dp=new int[n+1];
dp[0]=1;
dp[1]=1;
for(int i=2;i<=n;i++){
dp[i]=dp[i-1]+dp[i-2];
}
return dp[n];
}
}
遞歸：時(shí)間復(fù)雜度2^n
public class Main {
public static void climbstair(Stack<Integer> stack,int n){
if(n>=1){
stack.push(1);
climbstair(stack,n-1);
stack.pop();
}
if(n>=2){
stack.push(2);
climbstair(stack,n-2);
stack.pop();
}
if(n==0){
for(int i:stack){
System.out.println("step"+i+"->");
}
System.out.println("finish");
}
}
public static void main(String[] args) {
Stack<Integer> stack=new Stack<>();
climbstair(stack,5);
}
}
