poj Monthly Expense(二分)

#include <stdio.h>
#include <string.h>
#include <math.h>
int a[100010],l,r,n,m;
int check(int mon)
{
    int i=1,j,s;
    for(j=0,s=0;j<=n-1;j++)
        if((s+a[j])<=mon)
            s+=a[j];
        else
        {
            s=a[j];
            i++;
        }
    if(i<=m)
        return 1;
    return 0;
}
int binary_search()
{
    int mid;
    while(l<r)
    {
        mid=(l+r)/2;
        if(!check(mid))
            l=mid+1;
        else
            r=mid-1;
    }
    return l;
}
int main()
{
    int i,t;
    while(scanf("%d %d",&n,&m)!=EOF)
    {
        for(i=0,r=0,l=0;i<=n-1;i++)
        {
            scanf("%d",&a[i]);
            if(a[i]>l)
                l=a[i];
            r+=a[i];
        }
        t=binary_search();
        printf("%d\n",t);
    }
    return 0;
}