ZOJ-3721 Final Exam Arrangement 贪心

　　题目链接：http://acm.zju.edu.cn/onlinejudge/showProblem.do?problemCode=3721

　　容易的贪心题，排个序。。

 //STATUS:C++_AC_840MS_6272KB
 #include <functional>
 #include <algorithm>
 #include <iostream>
 //#include <ext/rope>
 #include <fstream>
 #include <sstream>
 #include <iomanip>
 #include <numeric>
 #include <cstring>
 #include <cassert>
 #include <cstdio>
 #include <string>
 #include <vector>
 #include <bitset>
 #include <queue>
 #include <stack>
 #include <cmath>
 #include <ctime>
 #include <list>
 #include <set>
 #include <map>
 using namespace std;
 //using namespace __gnu_cxx;
 //define
 #define pii pair<int,int>
 #define mem(a,b) memset(a,b,sizeof(a))
 #define lson l,mid,rt<<1
 #define rson mid+1,r,rt<<1|1
 #define PI acos(-1.0)
 //typedef
 //typedef __int64 LL;
 //typedef unsigned __int64 ULL;
 //const
 const int N=;
 const int INF=0x3f3f3f3f;
 const int MOD=,STA=;
 //const LL LNF=1LL<<60;
 const double EPS=1e-;
 const double OO=1e15;
 const int dx[]={-,,,};
 const int dy[]={,,,-};
 const int day[]={,,,,,,,,,,,,};
 //Daily Use ...
 inline int sign(double x){return (x>EPS)-(x<-EPS);}
 template<class T> T gcd(T a,T b){return b?gcd(b,a%b):a;}
 template<class T> T lcm(T a,T b){return a/gcd(a,b)*b;}
 template<class T> inline T lcm(T a,T b,T d){return a/d*b;}
 template<class T> inline T Min(T a,T b){return a<b?a:b;}
 template<class T> inline T Max(T a,T b){return a>b?a:b;}
 template<class T> inline T Min(T a,T b,T c){return min(min(a, b),c);}
 template<class T> inline T Max(T a,T b,T c){return max(max(a, b),c);}
 template<class T> inline T Min(T a,T b,T c,T d){return min(min(a, b),min(c,d));}
 template<class T> inline T Max(T a,T b,T c,T d){return max(max(a, b),max(c,d));}
 //End

 struct Node{
     int l,r;
     int idx;
     bool operator < (const Node &a)const {
         return l!=a.l?l<a.l:r<a.r;
     }
 }p[N];
 int cnt[N];
 vector<int> q[N];
 int n;

 int main()
 {
   //  freopen("in.txt","r",stdin);
     int i,j,tot,R;
     while(~scanf("%d",&n))
     {
         tot=;
         mem(cnt,);
         for(i=;i<=n;i++)q[i].clear();
         for(i=;i<n;i++){
             scanf("%d%d",&p[i].l,&p[i].r);
             p[i].idx=i+;
         }
         sort(p,p+n);

         R=-;
         for(i=;i<n;i++){
             if(p[i].l>=R){
                 tot++;
                 R=p[i].r;
             }
             R=Min(R,p[i].r);
             q[tot].push_back(p[i].idx);
             cnt[tot]++;
         }

         printf("%d\n",tot);
         for(i=;i<=tot;i++){
             printf("%d",q[i][]);
             for(j=;j<cnt[i];j++)
                 printf(" %d",q[i][j]);
             putchar('\n');
         }
         putchar('\n');
     }
     return ;
 }