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?

思路：当前第n步等于前n-1步走法 + 前n-2步走法，即f(n) = f(n-1) + f(n-2)

class Solution {
public:
int climbStairs(int n) {
// IMPORTANT: Please reset any member data you declared, as
// the same Solution instance will be reused for each test case.

if(n <= 1)
return 1;

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