51nod1128 正整数分组V2

 1 #include<cstdio>
 2 #include<algorithm>
 3 #define LL long long
 4 #define rg register
 5 #define N 200010
 6 int n,k,ans,a[N];
 7 LL l,r,mid;
 8 inline int read(){
 9     int k=0,f=1; char c=getchar();
10     while(c<‘0‘||c>‘9‘)c==‘-‘&&(f=-1),c=getchar();
11     while(‘0‘<=c&&c<=‘9‘)k=k*10+c-‘0‘,c=getchar();
12     return k*f;
13 }
14 inline bool check(){
15     int cnt=0; LL sum=0;
16     for(rg int i=1;i<=n;i++){
17         sum+=a[i];
18         if(sum>mid) cnt++,sum=a[i];
19     }
20     if(sum) cnt++;
21     //printf("%lld %d\n",mid,cnt);
22     return cnt<=k;
23 }
24 int main(){
25     n=read(); k=read();
26     for(rg int i=1;i<=n;i++) a[i]=read(),r+=a[i];
27     r++; l=0;
28     while(l+1<r){
29         mid=(l+r)>>1;
30         if(check()) r=mid; else l=mid;
31     }
32     printf("%lld\n",r);
33     return 0;
34 }