• 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)

    frame

    程序设计

    1. 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];
    	}
    }
    
    1. 初始化旅行商路径

    initGroup()//初始化路径编码

    1. 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);
    
    1. [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
    }
    
    1. [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
    
    1. 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++;
    }
    
    1. 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;
    }
    
    1. 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

    1. 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

    TEST

    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:

    传送门

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  • 原文地址:https://www.cnblogs.com/wsine/p/4676840.html
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