p1209 Barn Repair

用优先队列存放不连续的断点及断的位置。优先取间距大的，在断点断开。

#include <iostream>
#include <cstdio>
#include <cmath>
#include <algorithm>
#include <vector>
#include <iomanip>
#include <cstring>
#include <map>
#include <queue>
#include <set>
#include <cassert>
#include <stack>
#define mkp make_pair
using namespace std;
const double EPS=1e-;
typedef long long lon;
const lon SZ=,INF=0x7FFFFFFF;
lon arr[SZ],cut[SZ];

struct nd{
    int a,b;
    nd(int x,int y):a(x),b(y){}
    bool operator<(const nd &rbs)const
    {
        return a<rbs.a;
    }
};

int main()
{
    std::ios::sync_with_stdio();
    //freopen("d:\\1.txt","r",stdin);
    lon casenum;
    //cin>>casenum;
    //for(lon time=1;time<=casenum;++time)
    {
        lon k,tot,n;
        cin>>k>>tot>>n;
        priority_queue<nd> pq;
        for(int i=;i<=n;++i)
        {
            cin>>arr[i];
        }
        sort(arr+,arr++n);
        for(int i=;i<=n;++i)
        {
            if(i!=&&arr[i]-arr[i-]>)
            {
                pq.push(nd(arr[i]-arr[i-],i));
            }
        }
        for(;k!=;)
        {
            if(pq.empty())--k;
            else
            {
                nd pos=pq.top();
                pq.pop();
                //cout<<"pos.a: "<<pos.a<<endl;
                cut[pos.b]=;
                --k;
            }
        }
        int bg=;
        int res=;
        for(int i=;i<=n;++i)
        {
            if(cut[i])
            {
                //cout<<"i: "<<i<<endl;
                res+=arr[i-]-arr[bg]+;
                //cout<<(arr[i-1]-arr[bg]+1)<<endl;
                bg=i;
            }
        }
        res+=arr[n]-arr[bg]+;
        cout<<res<<endl;
    }
    return ;
}