1 #include<stdio.h>
2 #include<math.h>
3 #define MAXN 102
4 #define INF 1000000000
5 struct pos{
6 int x,y;
7 };
8 struct edge{
9 int v1,v2;
10 };
11 struct pos p[MAXN];
12 int g[MAXN][MAXN],vis[MAXN],n,d,flag,dist[MAXN],w[MAXN][MAXN],weight[MAXN],path[MAXN];
13 void init();
14 void read();
15 void creatg();
16 void dijkstra(int x);
17 double dis(struct pos p1,struct pos p2);
18 int main(){
19 int i;
20 flag=0;
21 read();
22 creatg();
23 dijkstra(0);
24 if(dist[n+1]!=INF){
25 printf("%d\n",dist[n+1]);
26 int stack[MAXN],top=0,pre;
27 pre = path[n+1];
28 while(pre!=0){
29 stack[top++] = pre;
30 pre = path[pre];
31 }
32 for(i=top-1;i>=0;i--){
33 pre = stack[i];
34 if(pre!=0&&pre!=n+1)
35 printf("%d %d\n",p[pre].x,p[pre].y);
36 }
37
38
39 }
40 else printf("0\n");
41 return 0;
42 }
43 void init(){
44 int i,j;
45
46 for(i=0;i<=n+1;i++)
47 for(j=0;j<=n+1;j++)
48 {
49 g[i][j] = INF;
50 w[i][j] = INF;
51 }
52 }
53 void read(){
54 int i,j;
55 scanf("%d %d",&n,&d);
56 init();
57 for(i=1;i<=n;i++)
58 scanf("%d %d",&p[i].x,&p[i].y);
59 }
60 double dis(struct pos p1,struct pos p2){
61 double temp;
62 temp = pow((p1.x-p2.x),2) + pow((p1.y-p2.y),2);
63 return sqrt(temp);
64 }
65 void creatg(){
66 int i,j;
67 double t;
68 struct pos o;
69 o.x = 0;
70 o.y = 0;
71 if((50-15.2)<=d){
72 g[0][n+1] = 1;
73 g[n+1][0] = 1;
74 w[0][n+1] = ceil((50-15.2));
75 w[n+1][0] = w[0][n+1];
76 }
77 for(i=1;i<=n;i++){
78 t = (dis(o,p[i])-15/2.0);
79
80 if(t<=d){
81 g[0][i] = 1;
82 g[i][0] = 1;
83 w[0][i] =ceil(t);
84 w[i][0] =ceil(t);
85 }
86
87
88 if((50-abs(p[i].x))<=d||((50-abs(p[i].y))<=d)){
89 g[i][n+1] = 1;
90 g[n+1][i] = 1;
91 w[i][n+1] = 1;
92 w[n+1][i] = 1;
93
94 }
95 }
96 for(i=1;i<=n;i++){
97 for(j=1;j<=n;j++){
98 if(i!=j && dis(p[i],p[j])<=d){
99 g[i][j] = 1;
100 g[j][i] = 1;
101 w[i][j] = 1;
102 w[j][i] = 1;
103 }
104 }
105 }
106 }
107 void dijkstra(int x){
108 int i,mdist,mn;
109 for(i=0;i<MAXN;i++) { dist[i] = INF; weight[i] = INF;}
110 for(i=0;i<=n+1;i++) vis[i]=0;
111 dist[x] = 0;
112 weight[x] =0;
113 while(1){
114 mdist = INF;
115 mn=-1;
116 for(i=0;i<=n+1;i++)
117 if(mdist > dist[i] && vis[i]==0 ){
118 mn = i;
119 mdist = dist[i];
120 }
121 vis[mn] = 1;
122 if(mn==-1) break;
123 for(i=0;i<=n+1;i++){
124 if(vis[i]==0){
125 if(g[mn][i]!=INF){
126 if(g[mn][i]+dist[mn]<dist[i]){
127 dist[i] = g[mn][i] + dist[mn];
128 weight[i] = w[mn][i] +weight[mn];
129 path[i] = mn;
130 }
131 else if(g[mn][i]+dist[mn]==dist[i]){
132 if(w[mn][i] + weight[mn] < weight[i]){
133 weight[i] = w[mn][i] +weight[mn];
134 path[i] = mn;
135 }
136 }
137 }
138 }
139 }
140
141 }
142
143
144 }
