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) {
/* 给定一个数n，有两种途径到达n
一，从n-1处，爬一阶楼梯到达n
二，从n-2处，爬两阶楼梯到达n*/
if (n==0)
return 0;
if (n==1)
return 1;
if (n==2)
return 2;
//int *step = new int [n+1];动态申请数组的两种方式
vector <int>step(n+1);
if(n>2)
{
step[0] = 0;
step[1] = 1;
step[2] = 2;
for (int i= 3;i<=n;i++)
step[i] = step[i-1] +step[i-2] ;
return step[n];
}
}
};