You are climbing a staircase. It takes n steps to reach the top. Each time you can either climb 1 or 2 steps. In how many distinct ways can you climb to the top?
class Solution {
public:
int climbStairs(int n) {
vector<int> dp(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];
}
};