poj3258River Hopscotch

http://poj.org/problem?id=3258

#include <iostream>
#include<cstdio>
#include<cstring>
#include<stdlib.h>
#include<cmath>
#include<algorithm>
using namespace std;
int st[50010],di[50010],n,m;
int judge(int mi)
{
    int i,k=0,s=0;
    for(i = 1; i <= n+1 ; i++)
    {
        s+=di[i];
        if(s<mi)
            k++;
        else
            s = 0;
    }
    if(k>m)
       return 1;
    else
       return 0;
}
int main()
{
    int i,ll;
    while(cin>>ll>>n>>m)
    {
        for(i = 1; i <= n ; i++)
        {
            cin>>st[i];
        }
        st[0] = 0;st[n+1] = ll;
        sort(st,st+n+2);
        int low = ll,high = ll;
        for(i = 1; i <= n+1 ; i++)
        {
           di[i] = st[i]-st[i-1];
           if(low>di[i])
              low = di[i];
        }
        int mid = (low+high)/2;
        while(low<=high)
        {
            if(judge(mid))
                high = mid-1;
            else
                low = mid+1;
            mid = (low+high)/2;
        }
        cout<<mid<<endl;
    }
    return 0;
}