模拟退火解决TSP问题

// monituihuo.cpp : 定义控制台应用程序的入口点。//#include "stdafx.h"#include <stdio.h>#include <stdlib.h>#include <math.h>#include <time.h>#include <iostream>#include <fstream>#include <Windows.h>using namespace std;const int MAXN = 27; //城市数量const double MAX = 27.0; //城市数量const double INIT_T = 3000; //初始温度const double RATE = 0.95; //温度衰减率const double FINNAL_T = 1E-10; //终止温度const int IN_LOOP = 15000; //内循环次数const int LIMIT = 10000; //概率选择上限const int FINL_LOOP = 1000; //外层循环double DD=0;double D_Length[MAXN][MAXN]={0};struct path{//定义路线结构    int citys[MAXN];    double length;}D_BestPath;struct point{//定义点结构    double x;    double y;}D_Point[MAXN];//计算点和点之间的距离void point_dist(){    int i, j;    double x;    for(i=0; i<MAXN; i++)    {        for(j=i+1; j<MAXN; j++)        {            x = (D_Point[i].x-D_Point[j].x)*(D_Point[i].x-D_Point[j].x);            x += (D_Point[i].y-D_Point[j].y)*(D_Point[i].y-D_Point[j].y);            D_Length[i][j] = sqrt(x);            D_Length[j][i] = D_Length[i][j];        }        }}//初始化void init(){    int i;    printf("初始状态路径：");    D_BestPath.length = 0;    for(i=0; i<MAXN; i++)    {//初始顺序经过路径        D_BestPath.citys[i] = i;        printf("%d--", i);    }    for(i=0; i<MAXN-1; i++)    {//计算路径长度        D_BestPath.length += D_Length[i][i+1];    }    printf("\n路径长度为：%.3lf\n\n", D_BestPath.length);            }void Dprintf(path p){//用于显示过程变化情况，打印    int i;    printf("路径是：");    for(i=0; i<MAXN; i++)    {        printf("%d--", p.citys[i]);    }    printf("\n路径长度为：%.3lf\n\n", p.length);}//输入城市坐标信息void input(){    int i,ll = 1;    ifstream f1("C:\\city.txt",ios::in);    for(i=0; i<MAXN; i++){        if(ll % 2 != 0)            f1 >> D_Point[i].x;        if(ll % 2 == 0)            f1 >> D_Point[i].y;        ll++;    }    f1.close();}path getnext(path p){    path ret;    int i,  x, y;    int te;    ret = p;    do    {        x = (int)(MAX*rand()/(RAND_MAX + 1.0));        y = (int)(MAX*rand()/(RAND_MAX + 1.0));    }    while(x == y);    te = ret.citys[x];    ret.citys[x] = ret.citys[y];    ret.citys[y] = te;    ret.length = 0;    for(i=0; i<MAXN-1; i++)    {//计算路径长度        ret.length += D_Length[ret.citys[i]][ret.citys[i+1]];    }    Dprintf(ret);    DD++;    return ret;}void sa(){    int i, P_L=0, P_F=0;;    path curPath, newPath;    double T = INIT_T;    double p, delta;    srand((int)time(0));    curPath = D_BestPath;    while(true)    {        for(i=0; i<IN_LOOP; i++)        {            newPath = getnext(curPath);            delta = newPath.length - curPath.length;            if(delta < 0)            {//更新长度                curPath = newPath;                P_L = 0;                P_F = 0;            }            else            {                p = (double)(1.0*rand()/(RAND_MAX+1.0));                if(exp(delta/T) < 1 && exp(delta/T) > p)                {                    curPath = newPath;                }                P_L ++;            }            if(P_L > LIMIT)            {                P_F ++;                break;            }        }        if(curPath.length < newPath.length)        {            D_BestPath = curPath;        }        if(P_F > FINL_LOOP || T<FINNAL_T)            break;        T = T * RATE;    }}void main(){    input();    point_dist();    init();    sa();    Dprintf(D_BestPath);    printf("\n共测试%.0lf次\n", DD);    system("pause");}