C++实现禁忌搜索解决TSP问题
C++实现禁忌搜索解决TSP问题
使用的搜索方法是Tabu Search（禁忌搜索）
程序设计
- 文件读入坐标点计算距离矩阵/读入距离矩阵
for(int i = 0; i < CityNum; i++){
fin >> x[i] >> y[i];
}
for(int i = 0; i < CityNum - 1; i++){
Distance[i][i] = 0;
for(int j = i + 1; j < CityNum; j++){
double Rij = sqrt(pow(x[i] - x[j], 2) + pow(y[i] - y[j], 2));
Distance[i][j] = Distance[j][i] = (int)(Rij + 0.5);//四舍五入
}
}
Distance[CityNum - 1][CityNum - 1] = 0;
for(int i = 0; i < CityNum; i++){
for(int j = 0; j < CityNum; j++){
fin >> Distance[i][j];
}
}
- 初始化旅行商路径
initGroup()//初始化路径编码
- 初始化最佳路径为初始化路径
// 假设为最优，如有更优则更新
memcpy(bestGh, Ghh, sizeof(int)*CityNum);
bestEvaluation = evaluate(Ghh);
- [有限次数迭代]，如达到搜索次数上限则结束搜索
// 有限次数迭代
int nn;
while(t < MAX_GEN){
// TSP solve
}
- [有限次数邻域交换]，随机交换两个路径点，如达次数转（7）
while(nn < NeighborNum){
changeneighbor(Ghh, tempGhh);// 得到当前编码Ghh的邻域编码tempGhh
- 禁忌表中不存在且路径更优，则更新当代路径，转（5）
if(!in_TabuList(tempGhh)){// 禁忌表中不存在
tempEvaluation = evaluate(tempGhh);
if(tempEvaluation < localEvaluation){// 局部更新
memcpy(LocalGhh, tempGhh, sizeof(int)*CityNum);
localEvaluation = tempEvaluation;
}
nn++;
}
- 如路径比最佳路径更优则更新最优路径
if(localEvaluation < bestEvaluation){// 最优更新
bestT = t;
memcpy(bestGh, LocalGhh, sizeof(int)*CityNum);
bestEvaluation = localEvaluation;
}
- 更新当代最优路径到当前路径（必定执行，可能更差）
memcpy(Ghh, LocalGhh, sizeof(int)*CityNum);// 可能更差，但同样更新
- 当前路径加入禁忌表，转（4）
pushTabuList(LocalGhh);// 加入禁忌表
t++;
程序加入了时间计算
start = clock();
solve();
finish = clock();
double run_time = (double)(finish - start) / CLOCKS_PER_SEC;
运行效果样例
默认搜索代数为10000
修改搜索代数可以线性控制搜索时间，但是搜索效果也会相应地改变，自行斟酌
完整代码
#include<iostream>
#include<string>
#include<fstream>
#include<cmath>
#include<ctime>
#include<cstdlib>
using namespace std;
int MAX_GEN;//迭代次数
int NeighborNum;//邻居数目
int TabuLen;//禁忌长度
int CityNum;//城市数量
int** Distance;//距离矩阵
int bestT;//最佳出现代数
int* Ghh;//初始路径编码
int* bestGh;//最好路径编码
int bestEvaluation;//最好路径长度
int* LocalGhh;//当代最好路径编码
int localEvaluation;//当代最后路径长度
int* tempGhh;//临时编码
int tempEvaluation;//临时路径长度
int** TabuList;//禁忌表
int t;//当前代数
string filename;
int DEBUG = 0;// for debug
void init(int argc, char** argv);
void solve();
void initGroup();
int evaluate(int* arr);
void changeneighbor(int* Gh, int*tempGh);
bool in_TabuList(int* tempGh);
void pushTabuList(int* arr);
void printResult();
void printDebug(int* arr, string message = "");
int main(int argc, char** argv)
{
init(argc, argv);
clock_t start, finish;
start = clock();
solve();
finish = clock();
double run_time = (double)(finish - start) / CLOCKS_PER_SEC;
printResult();
cout << "Runtime: " << run_time << " seconds" << endl;
system("pause");
return 0;
}
// 初始化各种参数
void init(int argc, char** argv){
// CMD大法好，CMD大法妙，CMD大法呱呱叫
filename = (argc >= 2) ? (string)(argv[1]) : "burma14.tsp";
int InputMode = (argc >= 3) ? atoi(argv[2]) : 0;
MAX_GEN = (argc >= 4) ? atoi(argv[3]) : 1000;
NeighborNum = (argc >= 5) ? atoi(argv[4]) : 200;
TabuLen = (argc >= 6) ? atoi(argv[5]) : 20;
// 打开文件
fstream fin(filename, ios::in);
if(!fin.is_open()){
cout << "Can not open the file " << filename << endl;
exit(0);
}
fin >> CityNum;
// 申请空间
Distance = new int* [CityNum];
for(int i = 0; i < CityNum; i++){
Distance[i] = new int[CityNum];
}
// 读入点坐标 计算距离矩阵
if(InputMode == 0){
double *x, *y;
x = new double[CityNum];
y = new double[CityNum];
for(int i = 0; i < CityNum; i++){
fin >> x[i] >> y[i];
}
for(int i = 0; i < CityNum - 1; i++){
Distance[i][i] = 0;
for(int j = i + 1; j < CityNum; j++){
double Rij = sqrt(pow(x[i] - x[j], 2) + pow(y[i] - y[j], 2));
Distance[i][j] = Distance[j][i] = (int)(Rij + 0.5);//四舍五入
}
}
Distance[CityNum - 1][CityNum - 1] = 0;
delete[] x;
delete[] y;
}
// 读入距离矩阵
else{
for(int i = 0; i < CityNum; i++){
for(int j = 0; j < CityNum; j++){
fin >> Distance[i][j];
}
}
}
// 申请空间 最佳路径无穷大
Ghh = new int[CityNum];
bestGh = new int[CityNum];
bestEvaluation = INT_MAX;
LocalGhh = new int[CityNum];
localEvaluation = INT_MAX;
tempGhh = new int[CityNum];
tempEvaluation = INT_MAX;
// 申请空间 迭代次数初始化0
TabuList = new int*[TabuLen];
for(int i = 0; i < TabuLen; i++){
TabuList[i] = new int[CityNum];
}
bestT = t = 0;
// 设置随机数种子
srand((unsigned int)time(0));
}
// 求解TSP问题
void solve(){
initGroup();//初始化路径编码
// 假设为最优，如有更优则更新
memcpy(bestGh, Ghh, sizeof(int)*CityNum);
bestEvaluation = evaluate(Ghh);
// 有限次数迭代
int nn;
while(t < MAX_GEN){
nn = 0;
localEvaluation = INT_MAX;// 初始化无穷大
while(nn < NeighborNum){
changeneighbor(Ghh, tempGhh);// 得到当前编码Ghh的邻域编码tempGhh
//if(++DEBUG < 10)printDebug(tempGhh, "after_change");
if(!in_TabuList(tempGhh)){// 禁忌表中不存在
tempEvaluation = evaluate(tempGhh);
if(tempEvaluation < localEvaluation){// 局部更新
memcpy(LocalGhh, tempGhh, sizeof(int)*CityNum);
localEvaluation = tempEvaluation;
}
nn++;
}
}
if(localEvaluation < bestEvaluation){// 最优更新
bestT = t;
memcpy(bestGh, LocalGhh, sizeof(int)*CityNum);
bestEvaluation = localEvaluation;
}
memcpy(Ghh, LocalGhh, sizeof(int)*CityNum);// 可能更差，但同样更新
pushTabuList(LocalGhh);// 加入禁忌表
t++;
}
//printResult();// 输出结果
}
// 初始化编码Ghh
void initGroup(){
// 默认从0号城市开始
for(int i = 0; i < CityNum; i++){
Ghh[i] = i;
}
//printDebug(Ghh, "init_Ghh");
}
// 计算路径距离
int evaluate(int* arr){
int len = 0;
for(int i = 1; i < CityNum; i++){
len += Distance[arr[i - 1]][arr[i]];
}
len += Distance[arr[CityNum - 1]][arr[0]];
return len;
}
// 得到当前编码Ghh的邻域编码tempGhh
void changeneighbor(int* Gh, int* tempGh){
int ran1 = rand() % CityNum;
while(ran1 == 0){
ran1 = rand() % CityNum;
}
int ran2 = rand() % CityNum;
while(ran1 == ran2 || ran2 == 0){
ran2 = rand() % CityNum;
}
int ran3 = rand() % 3;
// 随机交换一个数
if(ran3 == 0){
memcpy(tempGh, Gh, sizeof(int)*CityNum);
swap(tempGh[ran1], tempGh[ran2]);
}
// 随机交换中间一段距离
else if(ran3 == 1){
if(ran1 > ran2){
swap(ran1, ran2);
}
int Tsum = ran1 + ran2;
for(int i = 0; i < CityNum; i++){
if(i >= ran1&&i <= ran2){
tempGh[i] = Gh[Tsum - i];
}
else{
tempGh[i] = Gh[i];
}
}
}
// 随机交换一段距离
else if(ran3 == 2){
if(ran1 > ran2){
swap(ran1, ran2);
}
int index = 0;
for(int i = 0; i < ran1; i++){
tempGh[index++] = Gh[i];
}
for(int i = ran2 + 1; i < CityNum; i++){
tempGh[index++] = Gh[i];
}
for(int i = ran1; i <= ran2; i++){
tempGh[index++] = Gh[i];
}
}
}
// 判读编码是否在禁忌表中
bool in_TabuList(int* tempGh){
int i;
int flag = 0;
for(i = 0; i < TabuLen; i++){
flag = 0;
for(int j = 0; j < CityNum; j++){
if(tempGh[j] != TabuList[i][j]){
flag = 1;
break;
}
}
if(flag == 0)
break;
}
return !(i == TabuLen);
}
// 加入禁忌表
void pushTabuList(int* arr){
// 删除队列第一个编码
for(int i = 0; i < TabuLen - 1; i++){
for(int j = 0; j < CityNum; j++){
TabuList[i][j] = TabuList[i + 1][j];
}
}
// 加入队列尾部
for(int k = 0; k < CityNum; k++){
TabuList[TabuLen - 1][k] = arr[k];
}
}
// 输出结果
void printResult(){
fstream fout("TSP_AnswerOut.txt", ios::out);
fout << filename << " result:" << endl;
cout << "最佳长度出现代数：" << bestT << endl;
fout << "最佳长度出现代数：" << bestT << endl;
cout << "最佳路径长度： " << bestEvaluation << endl;
fout << "最佳路径长度： " << bestEvaluation << endl;
cout << "最佳路径：" << endl;
fout << "最佳路径：" << endl;
for(int i = 0; i < CityNum; i++){
cout << bestGh[i] << "->";
fout << bestGh[i] << "->";
}
cout << 0 << endl;
fout << 0 << endl;
fout.close();
}
// Only for Debug
void printDebug(int* arr, string message){
cout << message << ": ";
for(int i = 0; i < CityNum; i++){
cout << arr[i] << " ";
}
cout << endl;
}
测试样例
读入坐标
TabuSearch_TSP.exe burma14.tsp 0 10000 200 20
TabuSearch_TSP.exe ulysses16.tsp 0 1000 200 20
TabuSearch_TSP.exe ulysses22.tsp 0 1000 200 25
TabuSearch_TSP.exe eil51.tsp 0 1000 200 55
TabuSearch_TSP.exe dantzig42.tsp 0 1000 200 45
TabuSearch_TSP.exe att48.tsp 0 1000 200 50
TabuSearch_TSP.exe berlin52.tsp 0 1000 200 55
读入距离矩阵
TabuSearch_TSP.exe gr17.tsp 1 10000 500 20
TabuSearch_TSP.exe gr21.tsp 1 10000 500 25
TabuSearch_TSP.exe gr24.tsp 1 10000 500 25
TabuSearch_TSP.exe fri26.tsp 1 10000 500 30
TabuSearch_TSP.exe bayg29.tsp 1 10000 500 30
TabuSearch_TSP.exe bays29.tsp 1 10000 500 30
TabuSearch_TSP.exe swiss42.tsp 1 10000 500 45
TabuSearch_TSP.exe gr48.tsp 1 10000 500 50
TabuSearch_TSP.exe hk48.tsp 1 10000 500 50
TabuSearch_TSP.exe brazil58.tsp 1 10000 500 60
测试样例及完整代码：
