lintcode First Unique Number In Stream

First Unique Number In Stream

描述：

Given a continuous stream of numbers, write a function that returns the first unique number whenever terminating number is reached(include terminating number). If there no unique number before terminating number or you can't find this terminating number, return -1.

Given a stream [1, 2, 2, 1, 3, 4, 4, 5, 6] and a number 5
return 3

Given a stream [1, 2, 2, 1, 3, 4, 4, 5, 6] and a number 7
return -1

代碼：

 1 class Solution {
 2 public:
 3     /*
 4      * @param : a continuous stream of numbers
 5      * @param : a number
 6      * @return: returns the first unique number
 7      */
 8     int firstUniqueNumber(vector<int> nums, int number) {
 9         // Write your code here
10         bool flag = false;
11         int pos = 0; //用來記錄number的位置
12         for (int i = 0; i < nums.size(); i++) {
13             pos++;
14             if (number == nums[i]) {
15                 flag = true;
16                 break;
17             }
18         }
19         if (flag == false) return -1;
20 
21         map<int, int> s;
22         for (int i = 0; i < pos; i++) {
23             s[nums[i]]++;
24         }
25         for (int i = 0; i < pos; i++) {
26             if (s[nums[i]] == 1) {
27                 return nums[i];
28             }
29         }
30         return -1;
31     }
32 };