class Solution {
public:
    int splitArray(vector<int>& nums, int m) {
        long long lo = 0;
        long long hi = accumulate(nums.begin(), nums.end(), 0ll);

        while (hi - lo > 1) {
            auto mid = lo + (hi - lo) / 2;
            if (CanSplit(nums, m, mid)) hi = mid;
            else lo = mid;
        }

        return hi;
    }
private:
    bool CanSplit(const vector<int>& nums, int m, long long max_sum) {
        int curr_chunk_id = 1;
        long long curr_sum = 0;

        for (int i = 0; i < nums.size(); ++i) {
            if (nums[i] > max_sum) return false;
            if (curr_sum + nums[i] <= max_sum) {
                curr_sum += nums[i];
            } else {
                ++curr_chunk_id;
                curr_sum = nums[i];
            }
        }

        return curr_chunk_id <= m;
    }
};