No.27 Remove Element

 1 #include "stdafx.h"
 2 #include <map>
 3 #include <vector>
 4 #include <iostream>
 5 using namespace std;
 6 
 7 class Solution
 8 {
 9 public:
10     int removeElement(vector<int> &nums, int val)
11     {//移除数组中所有的给定数字
12      //要求：原地移除，不能使用额外空间；返回新数组的长度;可以改变原始顺序
13         int size = nums.size();
14         int count = 0;//计数当前val出现的次数
15 
16         for(int i=0; i<size; i++)
17         {
18             if(nums[i] == val)
19                 count++;
20             else
21             {
22                 if(count != 0)
23                     nums[i-count] = nums[i];
24             }
25         }
26         nums.erase(nums.begin()+size-count,nums.end());
27         return size-count;
28     }
29 };
30 
31 int main()
32 {
33     Solution sol;
34     int data[] = {1,2,2,3,3,2,1,7,9,10};
35     vector<int> test(data,data+sizeof(data)/sizeof(int));
36     for(const auto &i : test)
37         cout << i << " ";
38     cout << endl;
39     cout<< boolalpha << sol.removeElement(test,2)<<endl;
40         for(const auto &i : test)
41         cout << i << " ";
42     cout << endl;    
43 }