poj 3190 Stall Reservations1

来源：互联网发布：软件企业资质证书编辑：程序博客网时间：2024/06/10 17:30

堆 + 贪心

难得的好题，自己确实没想到，看了下别人的想法。.

http://www.acjoke.com/?p=164 这个链接的证明比较给力

#include<iostream>#include<cstdio>#include<cstring>#include<cmath>#include<vector>#include<queue>#include<stack>#include<algorithm>using namespace std;const int maxn = 50050;struct Line{    int l,r,index;    Line(const int& l = 0,const int& r = 0,const int&index = 0):l(l),r(r),index(index){}    Line(const Line& rsh)    {        l = rsh.l;        r = rsh.r;        index = rsh.index;    }    bool operator < (const Line& rsh) const    {        return l < rsh.l;    }};struct Heap{    int id;    int fin;    Heap(const int& id = 0 ,const int& fin = 0):id(id),fin(fin){}    Heap(const Heap& rsh)    {        id = rsh.id;        fin = rsh.fin;    }    bool operator < (const Heap& rsh) const    {        return fin > rsh.fin;    }};int result[maxn];vector<Line> lines;priority_queue<Heap> heaps;void put_cow( int i,bool flag){    Heap heap;    if(flag)    {        heap.id = heaps.size() + 1;    }    else    {        heap.id = heaps.top().id;        heaps.pop();    }    heap.fin = lines[i].r;    result[lines[i].index] = heap.id;    heaps.push(heap);}int main(){    #ifdef LOCAL        freopen("in.txt","r",stdin);    #endif // LOCAL    int n;    scanf("%d",&n);    int l,r;    for(int i = 0 ; i < n ; i ++)    {        scanf("%d %d",&l,&r);        lines.push_back(Line(l,r,i));    }    sort(lines.begin(),lines.end());    put_cow(0,true);    for(int i = 1 ; i < n ; i++)    {        put_cow(i,lines[i].l <= heaps.top().fin);    }    printf("%d\n",heaps.size());    for(int i = 0 ; i < n ; i++)    {        printf("%d\n",result[i]);    }    return 0;}

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