洛谷 1182 数列分段Section II

 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 int n,m,l,r,mid,a[N];
 9 inline int read(){
10     int 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 int max(int x,int y){return x>y?x:y;}
16 inline bool check(){
17     int sum=0,cnt=1;
18     for(rg int i=1;i<=n;i++){
19         sum+=a[i];
20         if(sum>mid) cnt++,sum=a[i];
21     }
22     return cnt<=m;
23 }
24 int main(){
25     n=read(); m=read();
26     for(rg int i=1;i<=n;i++) a[i]=read(),l=max(l,a[i]-1),r+=a[i];
27     while(l+1<r){
28         mid=(l+r)>>1;
29         if(check()) r=mid; else l=mid;
30     }
31     printf("%d\n",r);
32     return 0;
33 }