Stair Case Problem (DP)

 

You are climbing a stair case. It takes n steps to reach to the top.

Each time you can either climb 1 or 2 steps. In how many distinct ways can you climb to the top?

Example :

Input : 3

Return : 3

Steps : [1 1 1], [1 2], [2 1]

int Solution::climbStairs(int n) {

int dp[n];

if(n==0) return 1;

dp[0]=1;

dp[1]=2;

for(int i=2;i<n;i++){

dp[i]=dp[i-1]+dp[i-2];

}

return dp[n-1];

}