poj3273

#include 
#include 

using namespace std;

long long  n,m,a[100005];

long long   check(long long mid)
{
    long long total=0;
    long long s=0;
    for (int i=1;i<=n;)
    {
        while (s+a[i]<=mid&&i<=n) s+=a[i++];
        total++;s=0;
    }
    return total;
}

int main()
{   long long  left=0,right;
    long long sum=0;
    //freopen("in.txt","r",stdin);
    cin>>n>>m;
    for (int i=1;i<=n;i++)
    {
        cin>>a[i];
        sum+=a[i];
        if (a[i]>left) left=a[i];
    }
    right=sum;
    while (right-left>1)
    {
        long long mid;
        mid=(left+right)/2;
       // cout<
        if (check(mid)<=m) right=mid;else left=mid;
    }
    if (check(left)<=m) cout<<left;else cout<<right;


    return 0;
}

 题意:给定一个数列,要求把数列切分成m个段,使得总和最大的一段的总和最小。求这个总和。