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.

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Yes

样例

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

代码：

class Solution {
public:
    /*
     * @param : a continuous stream of numbers
     * @param : a number
     * @return: returns the first unique number
     */
    int firstUniqueNumber(vector<int> nums, int number) {
        // Write your code here
        bool flag = false;
        int pos = 0; //用来记录number的位置
        for (int i = 0; i < nums.size(); i++) {
            pos++;
            if (number == nums[i]) {
                flag = true;
                break;
            }
        }
        if (flag == false) return -1;

        map<int, int> s;
        for (int i = 0; i < pos; i++) {
            s[nums[i]]++;
        }
        for (int i = 0; i < pos; i++) {
            if (s[nums[i]] == 1) {
                return nums[i];
            }
        }
        return -1;
    }
};