1482.Minimum Number of Days to Make m Bouquets

題目敘述:

You are given an integer array bloomDay, an integer m and an integer k.

You want to make m bouquets. To make a bouquet, you need to use k adjacent flowers from the garden.

The garden consists of n flowers, the ith flower will bloom in the bloomDay[i] and then can be used in exactly one bouquet.

Return the minimum number of days you need to wait to be able to make m bouquets from the garden. If it is impossible to make m bouquets return -1.

class Solution {
public:
    int minDays(vector<int>& bloomDay, int m, int k) {
        if ((long long)m * k > bloomDay.size()) {
            return -1;
        }

        int low = 1, high = 1e9;
        while (low < high) {
            int mid = low + (high - low) / 2;

            if (canMakeBouquets(bloomDay, m, k, mid)) {
                high = mid;
            } else {
                low = mid + 1;
            }
        }

        return low;
    }

private:
    bool canMakeBouquets(vector<int>& bloomDay, int m, int k, int day) {
        int total = 0;
        for (int i = 0; i < bloomDay.size(); i++) {
            int count = 0;
            while (i < bloomDay.size() && count < k && bloomDay[i] <= day) {
                count++;
                i++;
            }

            if (count == k) {
                total++;
                i--;
            }

            if (total >= m) {
                return true;
            }
        }

        return false;
    }
};