数组： 
1 public:
 2     /**
 3      * @param A: a list of integers
 4      * @return : return an integer
 5      */
 6     int removeDuplicates(vector<int> &nums) {
 7         // write your code here
 8         int n=nums.size();int j;
 9         for(int i=0;i<n-1;i++){
10             for( j=1;j<n;j++){
11                 if(nums[i]==nums[j]){
12                     nums[j+1]=nums[i];
13                 }
14             }
15         }
16         nums.resize(j);
17         return j;
18 };

 1 class Solution {
 2 public:
 3     /**
 4      * @param n: An integer
 5      * @return: An integer
 6      */
 7     int climbStairs(int n) {
 8         // write your code here
 9         if(n == 0) return 1;
10         if(n <= 2) return n;
11          int b1,b2,b3;
12         b1 = 1;
13         b2 = 2;
14         for(int i = 2; i < n; ++i)
15         {
16           b3 = b1 + b2;
17           b1 = b2;
18           b2 = b3;
19         }
20         return b3;
21 
22     }
23 };