dp_tsp.rar_TSP问题_dp_tsp_tsp c++_旅行商问题 动态规划_路径规划

//用动态规划发解决TSP问题代码： #include <iostream> #include <set> #include <vector> #define MAX 6 using namespace std; int dis[MAX][MAX]={{0, 10, 20, 30, 40, 50},{12, 0 ,18, 30, 25, 21},{23, 19, 0, 5, 10, 15}, {34, 32, 4, 0, 8, 16},{45, 27, 11,10, 0, 18},{56, 22, 16,20, 12, 0}}; typedef struct { int curcity;//当前所在的城市 vector<int> unvisited;//当前未访问的城市 set<int> type;//由于set自动排序，相同状态的vector可能不同，但set必然相同 int distance;//从当前城市到终点回到起点的距离 }status; /*/**********测试用*************/ void printVec(vector<status> vec) { vector<status>::iterator iter; vector<int>::iterator it; for(iter=vec.begin();iter!=vec.end();iter++) { cout<<(*iter).curcity<<" <"; for(it=(*iter).unvisited.begin();it!=(*iter).unvisited.end();it++) { cout<<*it<<" "; } cout<<">"<<" distance:"<<(*iter).distance<<endl; } } bool contain(int i, status &sta) //看看当前状态的城市中是否包括城市i { vector<int>::iterator iter; if(i==sta.curcity) return true; else { for(iter=sta.unvisited.begin();iter!=sta.unvisited.end();iter++) if(i==*iter) return true; } return false; } vector<status> combine(vector<status> vec) /**//*合并相同状态*/ { vector<status> new_vec; vector<status>::iterator iter; status temp; while(vec.size()>0) { iter=vec.begin(); temp=*iter; vec.erase(iter); for(;iter!=vec.end();iter++) { if((temp.curcity==(*iter).curcity)&&(temp.type==(*iter).type)) { if((*iter).distance<temp.distance) temp=*iter; iter=vec.erase(iter); iter--; } } new_vec.push_back(temp); } return new_vec; } int main() { vector<status> pre_vector; vector<status> cur_vector; //从后往前推，初始化 for(int i=1;i<MAX;i++) { status sta; sta.curcity=i; sta.distance=dis[i][0]; cur_vector.push_back(sta); } //依次递推，递推MAX-2次 for(int j=0;j<MAX-2;j++) { pre_vector=cur_vector; cur_vector.clear(); for(int i=1;i<MAX;i++) { vector<status>::iterator iter; for(iter=pre_vector.begin();iter!=pre_vector.end();iter++) { status temp=*iter; if(contain(i,temp)==false)//为确保状态中没有重复路径 { status new_stat=temp; vector<int>::iterator int_iter=new_stat.unvisited.begin(); new_stat.unvisited.insert(int_iter,new_stat.curcity);//加入vector new_stat.type.insert(new_stat.curcity);//加入set new_stat.distance+=dis[i][new_stat.curcity];//计算距离 new_stat.curcity=i; cur_vector.push_back(new_stat); } } } cur_vector=combine(cur_vector); //记录相同状态最短路径，并合并相同状态 }//end for /**/ printVec(cur_vector); //递推完毕后，最后一步，计算起点到每个状态的距离，找到最短路径 vector<status>::iterator iter=cur_vector.begin(); status shortest=*iter; int min_dis=shortest.distance+dis[0][shortest.curcity]; iter++; for(;iter!=cur_vector.end();iter++) { int temp_dis=dis[0][(*iter).curcity]+(*iter).distance; if(temp_dis<min_dis) { min_dis=temp_dis; shortest=*iter; } } //打印结果 vector<int>::iterator iter_city; cout<<"minimum distance is "<<min_dis<<endl; cout<<"the shortest path is "<<"1 "<<shortest.curcity+1; for(iter_city=shortest.unvisited.begin();iter_city!=shortest.unvisited.end();iter_city++) cout<<" "<<*iter_city+1; cout<<" 1"<<endl; return 0; }