Climbing Stairs
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?
class Solution { public: int climbStairs(int n) { int a=1,b=1,t; for(int i=2;i<=n;i++){ t=a; a=a+b; b=t; } return a; } };