UVA216 ——dfs

来源：互联网发布：网站源代码怎么修改seo 编辑：程序博客网时间：2024/06/06 01:55
代码如下，注释很清楚，稍微学过数据结构的应该可以看懂
#include<iostream>#include<cmath>#include<cstring>#include<stdio.h>using namespace std;#define MAXNUM 9int x[MAXNUM],y[MAXNUM];//记录坐标double dis[MAXNUM][MAXNUM];//记录两点间距离，作为图的邻接矩阵int ans_order[MAXNUM];//存储dfs遍历节点的顺序int tem_order[MAXNUM];//临时存储dfs遍历节点的顺序double min_dis = 10000000;//最短距离int visit[MAXNUM];//记录节点是否被访问int n ;double distance(int x1,int y1,int x2,int y2){//两点间距离   return sqrt(pow( x1-x2 ,2)+pow(y1-y2,2));}void dfs(int cur){//对图进行第cur深度的深搜   if ( cur == n ){//如果深度超过图的节点个数，则对当前深搜所得到的连通图进行判断        double sum = 0 ;     for (int i = 0 ; i < n-1 ; i ++){//求当前所得连通图的代价，即题目题目中的step        sum+=dis[tem_order[i]][tem_order[i+1]];     }     if (sum < min_dis){        min_dis = sum ;        memcpy(ans_order,tem_order,sizeof(tem_order));     }   }else{//对图进行第cur深度的深搜    for( int i = 0 ; i < n ; i++){//遍历节点，找到下一个没有被访问的节点继续深度搜索       if(!visit[i]){        visit[i] = 1 ;        tem_order[cur] = i ;//当前深搜顺序的第cur个节点是i        dfs(cur+1);//对图进行第cur+1深度的深搜        visit[i] = 0;//相当于该节点退栈       }    }   }}int main (){   int time = 0;   while (cin>>n && n!=0){        time ++ ;    for (int i = 0  ; i < n ; i++){//输入并计算距离        scanf("%d %d",&x[i],&y[i]);        visit[i] = 0 ;        for (int j = 0 ; j < i ; j++){            dis[i][j] = dis[j][i] = distance(x[j],y[j],x[i],y[i]);        }    }    min_dis = 1000000;    dfs(0);       printf("**********************************************************\n");       printf("Network #%d\n",time);     for (int i = 0 ; i < n-1; i++){         printf("Cable requirement to connect (%d,%d) to (%d,%d) is %.2lf feet.\n",x[ans_order[i]],y[ans_order[i]],x[ans_order[i+1]],y[ans_order[i+1]],dis[ans_order[i]][ans_order[i+1]]+16);     }     printf("Number of feet of cable required is %.2lf.\n",min_dis+16*(n-1));   }   return 0;}
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