LEET code -- 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?

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int climbStairs(int n) { int stair[n+1]; stair[0]=1; stair[1]=1; // stair[2]=2; for(int i=2;i<=n;i++){ stair[i]=stair[i-1]+stair[i-2]; } return stair[n]; }