1482_Minimum_Number_of_Days_to_Make_m_Bouquets.cpp

#include <bits/stdc++.h>
using namespace std;

bool ifPossible(vector<int> &bloomDay, int val, int m, int k)
{
    int size = k;
    for (int i = 0; i < bloomDay.size(); i++)
    {
        if (!m)
            return true;
        if (bloomDay[i] <= val)
        {
            size--;
            if (!size)
            {
                size = k;
                m--;
            }
        }
        else
            size = k;
    }
    return (m <= 0) ? true : false;
}
int minDays(vector<int> &bloomDay, int m, int k)
{
    if ((long long)m * k > bloomDay.size())
        return -1;

    int minDay = *min_element(bloomDay.begin(), bloomDay.end());
    int maxDay = *max_element(bloomDay.begin(), bloomDay.end());
    int minimumDays = -1;

    int l = minDay, h = maxDay, mid;
    while (l <= h)
    {
        mid = (l + h) / 2;
        if (ifPossible(bloomDay, mid, m, k))
        {
            minimumDays = mid;
            h = mid - 1;
        }
        else
            l = mid + 1;
    }
    return minimumDays;
}