题目地址:点击打开链接
回溯就可以了,没什么好说的
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <cmath>
using namespace std;
int Point[10][2];
int A[10];
int n;
double min_length;
int min_length_point[10];
int visited[10];
int cas=1;
double distance_between_points(int a,int b)
{
int temp= (Point[a][0]-Point[b][0])*(Point[a][0]-Point[b][0])+
(Point[a][1]-Point[b][1])*(Point[a][1]-Point[b][1]);
return sqrt((double)temp);
}
void dfs(int val,double sum)
{
if(sum>=min_length)
return;
if(val==n)
{
if(sum<min_length)
{
min_length=sum;
copy(A,A+n,min_length_point);
return;
}
}
for(int i=0;i<n;++i)
{
if(visited[i]==0)
{
visited[i]=1;
*(A+val)=i;
if(val==0)
dfs(val+1,0);
else
{
double temp=distance_between_points(A[val-1],i);
dfs(val+1,sum+temp+16);
}
visited[i]=0;
}
}
}
void print()
{
printf("**********************************************************\n");
printf("Network #%d\n",cas++);
for(int i=0;i<n-1;++i)
printf("Cable requirement to connect (%d,%d) to (%d,%d) is %.2lf feet.\n",
Point[min_length_point[i]][0],Point[min_length_point[i]][1],
Point[min_length_point[i+1]][0],Point[min_length_point[i+1]][1],
distance_between_points(min_length_point[i],min_length_point[i+1])+16);
printf("Number of feet of cable required is %.2lf.\n",min_length);
}
int main()
{
while(scanf("%d",&n)!=EOF&&n!=0)
{
for(int i=0;i<n;++i)
scanf("%d %d",&Point[i][0],&Point[i][1]);
memset(visited,0,sizeof(visited));
min_length=2147483646;
dfs(0,0);
print();
}
return 0;
}