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Language:
Stall Reservations
Description
Oh those picky N (1 <= N <= 50,000) cows! They are so picky that each one will only be milked over some precise time interval A..B (1 <= A <= B <= 1,000,000), which includes both times A and B. Obviously, FJ must create a reservation system to determine which
stall each cow can be assigned for her milking time. Of course, no cow will share such a private moment with other cows.
Help FJ by determining:
Input
Line 1: A single integer, N
Lines 2..N+1: Line i+1 describes cow i‘s milking interval with two space-separated integers. Output
Line 1: The minimum number of stalls the barn must have.
Lines 2..N+1: Line i+1 describes the stall to which cow i will be assigned for her milking period. Sample Input 5 1 10 2 4 3 6 5 8 4 7 Sample Output 4 1 2 3 2 4 Hint
Explanation of the sample:
Here‘s a graphical schedule for this output: Time 1 2 3 4 5 6 7 8 9 10 Stall 1 c1>>>>>>>>>>>>>>>>>>>>>>>>>>> Stall 2 .. c2>>>>>> c4>>>>>>>>> .. .. Stall 3 .. .. c3>>>>>>>>> .. .. .. .. Stall 4 .. .. .. c5>>>>>>>>> .. .. ..Other outputs using the same number of stalls are possible. Source |
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#include<cstdio>
#include<iostream>
#include<algorithm>
#include<queue>
using namespace std;
const int maxn=50000+10;
int order[maxn];
struct Node
{
int st,en,pos;
friend bool operator<(Node a,Node b)
{
if(a.en==b.en)
return a.st<b.st;
return a.en>b.en;
}
}node[maxn];
bool cmp(Node a,Node b)
{
if(a.st==b.st)
return a.en<b.en;
else
return a.st<b.st;
}
priority_queue<Node>Q;
int main()
{
int n,ans;
while(~scanf("%d",&n))
{
for(int i=1;i<=n;i++)
{
scanf("%d%d",&node[i].st,&node[i].en);
node[i].pos=i;
}
sort(node+1,node+1+n,cmp);
ans=1;
Q.push(node[1]);
order[node[1].pos]=1;
for(int i=2;i<=n;i++)
{
if(!Q.empty()&&Q.top().en<node[i].st)
{
order[node[i].pos]=order[Q.top().pos];
Q.pop();
}
else
{
ans++;
order[node[i].pos]=ans;
}
Q.push(node[i]);
}
printf("%d\n",ans);
for(int i=1;i<=n;i++)
printf("%d\n",order[i]);
while(!Q.empty()) Q.pop();
}
return 0;
}
poj3190Stall Reservations(贪心+优先队列),布布扣,bubuko.com
poj3190Stall Reservations(贪心+优先队列)
原文：http://blog.csdn.net/u014303647/article/details/38342603