lintcode_138--Sub-array and zero

Title:

Given an array of integers, locate and zero the sub-array. Your code should return the starting and ending positions of the subarray that meet the requirements.

Sample Example Given [-3, 1, 2,-3, 4], return [0, 2] or [1, 3].

Problem Solving Ideas:

The prefix of the array is evaluated in turn and the following actions are performed:

Assuming that the current position is I, find the prefix of the position before I and, if there is a J position, so that the J position is prefixed with the prefix and equal to the I position.

If so, then the number of intervals between J and I is 0.

Until the complete array is traversed.

Time complexity O (n), spatial complexity O (n).

Implementation code:

Class Solution {public:    /**     * @param nums:a List of integers     * @return: A list of integers includes the index of the first number * and the index of the last number *    /vector<int> subarraysum (vector<int> ; Nums) {        //write your code here        int sum = 0;        vector<int> ret;        Unordered_map<int, int> map;        Map[0] =-1;        for (int i=0; i<nums.size (); i++)        {           sum + = nums[i];                      if (Map.find (sum)! = Map.end ())           {               ret.push_back (Map[sum] + 1);               Ret.push_back (i);               return ret;           }           Map[sum] = i;           }          return ret;    }};

lintcode_138--Sub-array and zero