Subsequence sum

Question

Given an array of integers eg [1, 2, -3, 1] find whether there is a sub-sequence that sums to 0 and return it (eg [1, 2, -3] or [2,

Answer 1

A C++ implementation with logic similar to Fabricio's answer.

pair FindSubsequenceSum(const vector& arr)      
{
  map sumMap;
  map::iterator it;
  int sum = 0;
  for (int i = 0; i < arr.size(); i++) 
  {
    sum += arr[i];
    it = sumMap.find(sum);
    if (it != sumMap.end()) 
    {
        return make_pair(it->second + 1, i);
    } else {
        sumMap.insert(make_pair(sum, i));
  }
}

int main()
{
  int arr[] = {1,4,-3,-4,6,-7,8,-5};
  vector input(arr, arr + sizeof(arr) / sizeof(arr[0]));
  pair result = FindSubsequenceSum(input);

  cout << "(" << result.first << "," << result.second << ")" << endl;

  return 0;
}

Output:
(2,6)