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#include <iostream>
#include <vector>

class Solution {
public:
    int minDays(std::vector<int>& bloomDay, int m, int k) {
        int n = bloomDay.size();
        if ((long long)m * k > n) {
            return -1;
        }
        int left = 1, right = 0;
        for (int d : bloomDay) {
            right = std::max(right, d);
        }
        
        for (int t = (left + right) / 2; right > left;) {
            if (check(bloomDay, k, m, t)) {
                right = t;
            }
            else {
                left = t + 1;
            }
            t = (left + right) / 2;
        }
        
        return left;
    }
    
private:
    bool check(std::vector<int>& bloomDay, int k, int m, int t) {
        int cur = 0;
        for (int d : bloomDay) {
            if (d <= t) {
                ++cur;
            }
            else {
                cur = 0;
            }
            if (cur == k) {
                --m;
                if (m == 0) {
                    return true;
                }
                cur = 0;
            }
        }
        return false;
    }
};