UVa216

純粋な列挙
すべての配列を列挙し、最小距離を記録します.
しかし、単一ソースの最短パスアルゴリズムがあるようです.

#include<stdio.h>
#include<math.h>
#define Maxnode 9
#define INF 100000
int ans[Maxnode];
int a[Maxnode];
double distance[Maxnode],ansdistance[Maxnode];
int nodes;
double maxdist;
struct node{
	int x,y;
}vector[Maxnode];
void dfs(int cur){
	int i,ok,j;
	double xdis,ydis,dist,total_dis;
	if(cur==nodes+1){
		for(i=1,total_dis=0;i<nodes;i++){
			xdis=vector[a[i]].x-vector[a[i+1]].x;
			ydis=vector[a[i]].y-vector[a[i+1]].y;
			dist=sqrt(xdis*xdis+ydis*ydis);
			distance[i]=dist=dist+16;
			total_dis +=dist;
		}
		if(total_dis<maxdist){
			maxdist=total_dis;
			for(i=1;i<=nodes;i++){
				ans[i]=a[i];
			}
			for(i=1;i<nodes;i++){
				ansdistance[i]=distance[i];
			}
		}
		return ;
	}
	else{                               //       
		for(i=1;i<=nodes;i++){
		ok=1;
		a[cur]=i;
		for(j=1;j<cur;j++){
			if(a[j]==a[cur]){
				ok=0;
				break;
			}
		}
		if(ok)
			dfs(cur+1);
		}
	}
}
int main()
{
	int i,case_num=1;
	while(scanf("%d",&nodes)!=EOF&&nodes){
		maxdist=INF;
		for(i=1;i<=nodes;i++){
			scanf("%d %d",&vector[i].x,&vector[i].y);
		}
		dfs(1);
		printf("**********************************************************
");
		printf("Network #%d
",case_num);
		for(i=1;i<nodes;i++){
			printf("Cable requirement to connect (%d,%d) to (%d,%d) is %.2f feet.
",vector[ans[i]].x,vector[ans[i]].y,vector[ans[i+1]].x,vector[ans[i+1]].y,ansdistance[i]);
		}
		printf("Number of feet of cable required is %.2f.
",maxdist);
		case_num++;
	}
	return 0;
}