链接：
[2594. 修车的最少时间](https://leetcode.cn/problems/minimum-time-to-repair-cars/)\](https://leetcode.cn/problems/form-smallest-number-from-two-digit-arrays/)
**题意：**
一个能力R的人R\*N\*N分钟修N辆车，求最快多久修完（多人多车）
**解：**
二分很好想，主要是怎么检查(数学废物润去看题解了)
**实际代码：**
```c++
long long repairCars(vector& ranks, int cars)
{
typedef long long int ll;
sort(ranks.begin(),ranks.end());
ll l=1,r=1ll*ranks[ranks.size()-1]*pow(cars,2);
while(l>1;
ll cnt=0;
for(auto rank:ranks) cnt+=sqrt(m/rank);
if(cnt>=cars) r=m;
else l=m+1;
}
return l;
}
```
限制：
* `1 <= ranks.length <= 105`
* `1 <= ranks[i] <= 100`
* `1 <= cars <= 106`