2256.cpp

#include <numeric>
#include <vector>
using namespace std;
using big_type = long long;
int abs_sub(big_type a, big_type b) { return a > b ? a - b : b - a; }

class Solution {
 public:
  int minimumAverageDifference(vector<int>& nums) {
    vector<big_type> all_sum(nums.size(), 0), avg(nums.size(), 0), nums_;
    for (const auto& n : nums) nums_.push_back(n);
    partial_sum(nums_.begin(), nums_.end(), all_sum.begin());
    for (int i = 0; i < all_sum.size(); i++) {
      int avg1 = all_sum[i] / (i + 1);
      int avg2 = i == all_sum.size() - 1
                     ? 0
                     : (all_sum.back() - all_sum[i]) / (all_sum.size() - i - 1);
      avg[i] = abs_sub(avg1, avg2);
    }
    int ret = 0;
    for (int i = 0; i < avg.size(); i++) ret = avg[ret] > avg[i] ? i : ret;
    return ret;
  }
};