Problem p02258 (C++)

Buggy submission (status: Runtime Error):
//
// Created by sanyinchen on 17/4/17.
//

#include <cstdio>
#include <iostream>
#include <limits>
#include <string.h>
#include <vector>

using namespace std;

vector<int> findMaxWithMidPoint(int *array, int low, int high) {

  int mid = (low + high) / 2;
  int leftSum = 0, leftLow = mid;
  int rightSum = 0, rightHigh = mid + 1;
  int maxLeft = array[leftLow], maxRight = array[rightHigh];

  vector<int> res;
  for (int i = mid; i >= low; i--) {
    leftSum += array[i];
    if (leftSum > maxLeft) {
      maxLeft = leftSum;
      leftLow = i;
    }
  }
  res.push_back(leftLow);

  for (int i = mid + 1; i <= high; i++) {
    rightSum += array[i];
    if (rightSum > maxRight) {
      maxRight = rightSum;
      rightHigh = i;
    }
  }
  res.push_back(rightHigh);
  //    cout << low << " " << high << endl;
  //    cout << "sum:" << maxLeft + maxRight << " left:" << leftLow << " " <<
  //    "high:" << rightHigh << endl;
  res.push_back(maxLeft + maxRight);

  return res;
}

vector<int> findMax(int *array, int low, int high) {

  if (low == high) {

    vector<int> res;
    res.push_back(low);
    res.push_back(high);
    res.push_back(array[low]);
    return res;
  } else {
    int mid = (low + high) / 2;

    vector<int> left = findMax(array, low, mid);
    vector<int> right = findMax(array, mid + 1, high);
    vector<int> midRes = findMaxWithMidPoint(array, low, high);
    //        cout << "left:" << left[0] << " " << left[1] << " " << left[2] <<
    //        endl; cout << "right:" << right[0] << " " << right[1] << " " <<
    //        right[2] << endl; cout << "midRes:" << midRes[0] << " " <<
    //        midRes[1] << " " << midRes[2] << endl;

    if (left[2] >= right[2] && left[2] >= midRes[2]) {
      return left;
    }
    if (right[2] >= left[2] && right[2] >= midRes[2]) {

      return right;
    }

    return midRes;
  }
}

int main() {
  freopen("../files/in.txt", "r", stdin);
  int input[200001] = {0};
  int data[200001] = {0};
  int n;
  cin >> n;
  for (int i = 0; i < n; i++) {
    cin >> input[i];
    if (i == 0) {
      data[i] = 0 - input[i];
    } else {
      data[i] = input[i] - input[i - 1];
    }
  }
  //    for (int i = 0; i < n; i++) {
  //        cout << data[i] << " ";
  //    }
  // cout << endl;
  vector<int> res = findMax(data, 0, n - 1);
  // cout << res[0] << " " << res[1] << " " << res[2] << endl;
  cout << res[2] << endl;

  return 0;
}

Fixed submission:
//
// Created by sanyinchen on 17/4/17.
//

#include <cstdio>
#include <iostream>
#include <limits>
#include <string.h>
#include <vector>

using namespace std;

vector<int> findMaxWithMidPoint(int *array, int low, int high) {

  int mid = (low + high) / 2;
  int leftSum = 0, leftLow = mid;
  int rightSum = 0, rightHigh = mid + 1;
  int maxLeft = array[leftLow], maxRight = array[rightHigh];

  vector<int> res;
  for (int i = mid; i >= low; i--) {
    leftSum += array[i];
    if (leftSum > maxLeft) {
      maxLeft = leftSum;
      leftLow = i;
    }
  }
  res.push_back(leftLow);

  for (int i = mid + 1; i <= high; i++) {
    rightSum += array[i];
    if (rightSum > maxRight) {
      maxRight = rightSum;
      rightHigh = i;
    }
  }
  res.push_back(rightHigh);
  //    cout << low << " " << high << endl;
  //    cout << "sum:" << maxLeft + maxRight << " left:" << leftLow << " " <<
  //    "high:" << rightHigh << endl;
  res.push_back(maxLeft + maxRight);

  return res;
}

vector<int> findMax(int *array, int low, int high) {

  if (low == high) {

    vector<int> res;
    res.push_back(low);
    res.push_back(high);
    res.push_back(array[low]);
    return res;
  } else {
    int mid = (low + high) / 2;

    vector<int> left = findMax(array, low, mid);
    vector<int> right = findMax(array, mid + 1, high);
    vector<int> midRes = findMaxWithMidPoint(array, low, high);
    //        cout << "left:" << left[0] << " " << left[1] << " " << left[2] <<
    //        endl; cout << "right:" << right[0] << " " << right[1] << " " <<
    //        right[2] << endl; cout << "midRes:" << midRes[0] << " " <<
    //        midRes[1] << " " << midRes[2] << endl;

    if (left[2] >= right[2] && left[2] >= midRes[2]) {
      return left;
    }
    if (right[2] >= left[2] && right[2] >= midRes[2]) {

      return right;
    }

    return midRes;
  }
}

int main() {
  // freopen("../files/in.txt", "r", stdin);
  int input[200001] = {0};
  int data[200001] = {0};
  int n;
  cin >> n;
  for (int i = 0; i < n; i++) {
    cin >> input[i];
    if (i == 0) {
      data[i] = 0 - input[i];
    } else {
      data[i] = input[i] - input[i - 1];
    }
  }
  //    for (int i = 0; i < n; i++) {
  //        cout << data[i] << " ";
  //    }
  // cout << endl;
  vector<int> res = findMax(data, 0, n - 1);
  // cout << res[0] << " " << res[1] << " " << res[2] << endl;
  cout << res[2] << endl;

  return 0;
}