Borg Maze - poj 3026(BFS + Kruskal 算法)

  1 #include<stdio.h>
  2 #include<string.h>
  3 #include<queue>
  4 #include<algorithm>
  5 #include <iostream>
  6 using namespace std;
  7 int map[102][102];
  8 int vis[102][102];
  9 int parent[102];
 10 int row, col;
 11 int edge_num = 0;
 12 int point_num=0;
 13 struct edge {
 14     int u, v, w;
 15 } e[102 * 102];
 16 struct points {
 17     int u, v, d;
 18 } point;
 19 bool cmp(const edge e1,const edge e2){
 20     return e1.w<e2.w;
 21 }
 22 int Kruskal(){
 23     int mindis=0;
 24     for(int i=1;i<=point_num;i++){
 25         parent[i]=i;
 26     }
 27     sort(e,e+edge_num,cmp);
 28     int pnum=0;
 29     for(int i=0;i<edge_num&&pnum<point_num;i++){
 30         int k,g;
 31         int u=e[i].u;
 32         int v=e[i].v;
 33         for(k=parent[u];parent[k]!=k;k=parent[parent[k]]);
 34         for(g=parent[v];parent[g]!=g;g=parent[parent[g]]);
 35 
 36         if(k!=g){
 37             parent[g]=k;
 38             mindis+=e[i].w;
 39             pnum++;
 40         }
 41         }
 42     return mindis;
 43 }
 44 void BFS(int x, int y) {
 45     queue<points> p;
 46     points s;
 47     s.u = x;
 48     s.v = y;
 49     s.d = 0;
 50     p.push(s);
 51     memset(vis, 0, 102 * 102 * sizeof(int));
 52     vis[x][y] = 1;
 53 
 54     while (!p.empty()) {
 55         points tmp = p.front();
 56         p.pop();
 57         for (int i = -1; i < 2; i += 2) {
 58             points next;
 59             next.u = tmp.u + i;
 60             next.v = tmp.v;
 61             next.d = tmp.d + 1;
 62             if (next.u >= 0 && next.u < row) {
 63                 if (!vis[next.u][next.v]) {
 64                     int pos = map[next.u][next.v];
 65                     vis[next.u][next.v] = 1;
 66                     if (pos >= 0)
 67                         p.push(next);
 68                     if (pos >= 1) {
 69                         e[edge_num].u = map[x][y];
 70                         e[edge_num].v = pos;
 71                         e[edge_num].w = next.d;
 72                         edge_num++;
 73                     }
 74                 }
 75             }
 76         }
 77         for (int i = -1; i < 2; i += 2) {
 78             points next;
 79             next.u = tmp.u;
 80             next.v = tmp.v + i;
 81             next.d = tmp.d + 1;
 82             if (next.v >= 0 && next.v < col) {
 83                 if (!vis[next.u][next.v]) {
 84                     int pos = map[next.u][next.v];
 85                     vis[next.u][next.v] = 1;
 86                     if (pos >= 0)
 87                         p.push(next);
 88                     if (pos >= 1) {
 89                         e[edge_num].u = map[x][y];
 90                         e[edge_num].v = pos;
 91                         e[edge_num].w = next.d;
 92                         edge_num++;
 93                     }
 94                 }
 95             }
 96         }
 97 
 98     }
 99 }
100 int main() {
101     int n;
102     scanf("%d", &n);
103     char tmp[102];
104     for (int i = 0; i < n; i++) {
105         point_num=0;
106         edge_num=0;
107         scanf("%d %d", &col, &row);
108         gets(tmp); //坑【一串空格】
109         for (int j = 0; j < row; j++) {
110             for (int k = 0; k < col; k++) {
111                 char c;
112                 scanf("%c", &c);
113                 if (c == ‘ ‘)
114                     map[j][k] = 0;
115                 else if (c == ‘#‘)
116                     map[j][k] = -1;
117                 else if (c == ‘\n‘)
118                     k--;
119                 else
120                     map[j][k] = ++point_num;
121             }
122 
123         }
124         for (int j = 0; j < row; j++) {
125             for (int k = 0; k < col; k++) {
126                 if (map[j][k] > 0) {
127                     BFS(j, k);
128                 }
129             }
130         }
131         int mid=Kruskal();
132         printf("%d\n",mid);
133     }
134     return 0;
135 }