最少教室问题与区间图着色问题类似

#include<iostream>#include <limits>#include<ctime>using namespace std;typedef struct list{int tag;//教室编号int time;//活动的结束时间list *next;//下一个活动}list ,*plist;void minimum_lecture_hall(plist &busing,plist &free,int *s,int *f,int * lecture_hall,int &lecture_hall_no,int n)//最小教室问题与区间图着色问题类似{//busing指向正在有活动的教室，free指向当前无活动的教室plist tmpnode,tnode,prenode;for(int i=0;i<n;++i){tmpnode=busing->next;//指向有活动的教室的首节点prenode=busing;//前一节点while(tmpnode){if(tmpnode->time<=s[i]){tnode=tmpnode->next;tmpnode->next=free->next;free->next=tmpnode;prenode->next=tnode;tmpnode=prenode;}prenode=tmpnode;tmpnode=tmpnode->next;}if(free->next){//free链表中有空余的教室tmpnode=free->next;tmpnode->time=f[i];//活动结束时间free->next=free->next->next;tmpnode->next=busing->next;busing->next=tmpnode;//将其添加到活动的链表lecture_hall[i]=tmpnode->tag;//存储当前活动所在的教室编号}else{//否则无多余教室，则需要另外添加教室,并将其添加到活动链表中tmpnode=new list;tmpnode->time=f[i];tmpnode->tag=lecture_hall_no++;//教室编号tmpnode->next=busing->next;busing->next=tmpnode;lecture_hall[i]=tmpnode->tag;//存储当前活动所在的教室编号}}}void quick_sort(int *s,int *f,int low,int high)//快速排序，安装活动的开始时间升序排序{while (low<high){int pivot=s[high];int k=low-1;int tmp;for(int i=low;i<high;++i){if(s[i]<=pivot){++k;tmp=s[i];s[i]=s[k];s[k]=tmp;tmp=f[i];f[i]=f[k];f[k]=tmp;}}tmp=s[high];s[high]=s[k+1];s[k+1]=tmp;tmp=f[high];f[high]=f[k+1];f[k+1]=tmp;if((k-low)<(high-k-2)){//栈深度为O(lgn)quick_sort(s,f,low,k);low=k+2;}else{quick_sort(s,f,k+2,high);high=k;}}}void sort_final_time(int *s,int *f,int n)//按照结束时间排序{int low=0,high=0,tmp;for(int i=1;i<=n;++i){if(s[i]!=s[i-1]){low=i;}else{high=i;tmp=f[i];while (high>low && tmp<f[high-1]){//开始时间相同，结束时间进行插入排序f[high]=f[high-1];--high;}f[high]=tmp;/*for(int j=low;j<=i;++j){cout<<s[j]<<" ";}cout<<endl;for(int j=low;j<=i;++j){cout<<f[j]<<" ";}cout<<endl;*/}}}int main(){srand((unsigned)time(NULL));int n=11;int *s=new int[n];int *f=new int[n];/*s[0]=1,s[1]=3,s[2]=0,s[3]=5,s[4]=3,s[5]=5,s[6]=6,s[7]=8,s[8]=8,s[9]=2,s[10]=12;f[0]=4,f[1]=5,f[2]=6,f[3]=7,f[4]=9,f[5]=9,f[6]=10,f[7]=11,f[8]=12,f[9]=14,f[10]=16;*/for(int i=0;i<n;++i){s[i]=rand()%n+1;//活动i开始时间f[i]=rand()%(n/2)+1+s[i];//活动i结束时间}quick_sort(s,f,0,n-1);//按照开始时间排序sort_final_time(s,f,n-1);//按照结束时间排序/*s[0]=0,s[1]=1,s[2]=2,s[3]=3,s[4]=3,s[5]=5,s[6]=5,s[7]=6,s[8]=8,s[9]=8,s[10]=12;f[0]=6,f[1]=4,f[2]=14,f[3]=5,f[4]=9,f[5]=7,f[6]=9,f[7]=10,f[8]=11,f[9]=12,f[10]=16;*/for(int i=0;i<n;++i){cout<<s[i]<<"\t";}cout<<endl;for(int i=0;i<n;++i){cout<<f[i]<<"\t";}cout<<endl;plist busing=new list;//指向正有活动的教室busing->next=NULL;plist free=new list;//指向无活动的教室free->next=NULL;int lecture_hall_no=0;//当前使用的教室编号int *lecture_hall=new int[n];//为每个活动存储教室编号minimum_lecture_hall(busing,free,s,f,lecture_hall,lecture_hall_no,n);for(int i=0;i<n;++i){cout<<"active "<<i<<" : [ "<<s[i]<<" , "<<f[i]<<" )"<<" is arranged in lecture hall "<<lecture_hall[i]<<endl;}delete []s;delete []f;delete [] lecture_hall;plist ls=busing;while(ls){busing=busing->next;delete ls;ls=busing;}ls=free;while(ls){free=free->next;delete ls;ls=free;}}