1482. 制作 m 束花所需的最少天数(经典二分+验证答案)

class Solution {
public:
    int minDays(vector<int>& bloomDay, int m, int k) {
        int len = bloomDay.size();
        if(len < m * k) return -1;
        int l = 0,r = 0;
        for(int b:bloomDay){
            r = max(r,b);
            l = min(l,b);
        }
        while(l<r){
          int mid = (r-l)/2+l;
          if(check(bloomDay,m,k,mid)){
              r = mid;
          }
          else{
              l = mid + 1;
          }
        }
        return l;
    }
    
    bool check(vector<int>& bloomDay,int m,int k,int day){
         int flower = 0;
         int num = 0;
         for(int b:bloomDay){
             if(b<=day){
                 flower++;
                 if(flower == k){
                     num++;
                     flower = 0;
                 }
             }
             else{
                 flower = 0;
             }
         }
         return num >= m;
    }

};