洛谷 2440 木材加工

 1 #include<cstdio>
 2 #include<algorithm>
 3 #include<cstring>
 4 #define LL long long
 5 #define rg register
 6 #define N 200010
 7 using namespace std;
 8 LL n,m,l,r,mid,a[N];
 9 inline LL read(){
10     LL k=0,f=1; char c=getchar();
11     while(c<‘0‘||c>‘9‘)c==‘-‘&&(f=-1),c=getchar();
12     while(‘0‘<=c&&c<=‘9‘)k=k*10+c-‘0‘,c=getchar();
13     return k*f;
14 }
15 inline bool check(){
16     LL sum=0;
17     for(rg int i=1;i<=n;i++){
18         sum+=a[i]/mid;
19         if(sum>=m) return 1;
20     }
21     return 0;
22 }
23 int main(){
24     n=read(); m=read();
25     for(rg int i=1;i<=n;i++) a[i]=read(),r+=a[i];
26     while(l+1<r){
27         mid=(l+r)>>1;
28         if(check()) l=mid;
29         else r=mid;
30     }
31     printf("%lld",l);
32     return 0;
33 }