ACM Stall Reservations(挑战程序设计竞赛)

Stall Reservations

Time Limit: 1000ms

Memory Limit: 65536KB

This problem will be judged on  PKU. Original ID:  3190
64-bit integer IO format:  %lld      Java class name:  Main

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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:

• The minimum number of stalls required in the barn so that each cow can have her private milking period
• An assignment of cows to these stalls over time

Many answers are correct for each test dataset; a program will grade your answer.

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

Source

USACO 2006 February Silver

#include 
#include 
#include 
#include 

using namespace std;

#define MAX_N 50000
#define INF 99999999

int n;
int barnID[MAX_N];

struct Cow
{
    int s,t;
    int ID;
} cow[MAX_N];

bool cmp(const Cow &a,const Cow &b)
{
    if(a.s!=b.s)
        return a.sb.t;
}

priority_queue ss;

int main()
{
    scanf("%d",&n);

    for(int i=0;i