【openjudge 8209】月度开销

比较……额……
验证的时候要记得，最后一组也是要统计的
WA On 7应该就是这个问题了

#include 
#include 
#include 
#include 
using namespace std;
const int MAXN = 100000 + 5;
int n;
int num[MAXN],m;
bool can(int x)
{
    int k = 0,now = 0;
    for(int i = 1;i <= n;i ++)
        if(now + num[i] > x)
            k ++,now = num[i];
        else
            now += num[i];
    k ++;//就是这里！！！
    return k <= m;
}
int diver(int l,int r)
{
    int ans = 0;
    while(l <= r)
    {
        int mid = l + r >> 1;
        if(can(mid))
            ans = mid,r = mid - 1;
        else
            l = mid + 1;
    }
    return ans;
}
int main()
{
    scanf("%d %d",&n,&m);
    for(int i = 1;i <= n;i ++)
        scanf("%d",&num[i]);
    int l = 0,r = 0;
    for(int i = 1;i <= n;i ++)
        l = max(l,num[i]),r += num[i];
    printf("%d\n",diver(l,r));
    return 0;
}