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pop 2049-简单bfs

思路:

将边当作点,这样建墙的时候点的坐标变换成x' = 2*x-1, y' = 2*y-1,t' = 2*t,  建门同理,但是因为门只要开一格就行所以t还是1。nemo的位置变换后是下取整x,y坐标各+1,

然后 1代表墙,2代表门,4代表nemo。这题坑在nemo的范围不知道,所以不能直接在开的建图的数组里找,我就这样RE了好多次,不在图的范围里的直接可以判断输出0。然后用优先队列存经过的点,按经过的门次数升序排序。

pop 2049-简单bfs
pop 2049-简单bfs
1 #include <iostream>
  2 #include <cstdio>
  3 #include <queue>
  4 #include <vector>
  5 #include <cmath>
  6 #include <cstring>
  7 #include <string>
  8 #include <algorithm>
  9 using namespace std;
 10 
 11 int arr[500][500], minStep;
 12 bool vis[500][500];
 13 int dir[4][2] = {{-1, 0}, {1, 0}, {0, -1}, {0, 1}};
 14 struct node
 15 {
 16     int x, y,step;
 17     node(){
 18         x = y = step = 0;
 19     }
 20     bool operator == (node that){
 21         if(that.x == x && that.y == y) return true;
 22         return false;
 23     }
 24     bool operator < (const node &that) const
 25     {
 26         return step > that.step;
 27     }
 28 };
 29 
 30 void init()
 31 {
 32     memset(arr, 0, sizeof(arr));
 33     memset(vis, 0, sizeof(vis));
 34     minStep = 160000;
 35 }
 36 void build_wall(int xx, int yy, int dd, int tt)
 37 {
 38     int x = 2*xx-1, y = 2*yy-1;
 39     if(dd)
 40         for(int i = y; i <= y+2*tt; i++)
 41             arr[x][i] = 1;
 42     else
 43         for(int i = x; i <= x+2*tt; i++)
 44             arr[i][y] = 1;
 45 }
 46 void door(int xx, int yy, int dd)
 47 {
 48     int x = 2 * xx -1, y = 2 * yy -1;
 49     if(dd) arr[x][y+1] = 2;
 50     else arr[x+1][y] = 2;
 51 }
 52 bool checkBound(int x, int y)
 53 {
 54     if(x < 0||y < 0||x>400||y>400) return false;
 55     return true;
 56 }
 57 void findNemo()
 58 {
 59     node nd, nd2;
 60     vis[0][0] = 1;
 61     priority_queue<node> q;
 62     q.push(nd);
 63     while(!q.empty()){
 64         nd = q.top(); q.pop();
 65         for(int i = 0; i < 4; i++) {
 66             int x = dir[i][0] + nd.x, y = dir[i][1] + nd.y;
 67             if(checkBound(x, y) && arr[x][y] != 1 && !vis[x][y]) {
 68                 nd2.step = nd.step; nd2.x = x; nd2.y = y;
 69                 vis[x][y] = 1;
 70                 if(arr[x][y] == 2) nd2.step++;
 71                 q.push(nd2);
 72                 if(arr[x][y] == 4) {
 73                     vis[x][y] = 0;
 74                     minStep = nd2.step;
 75                     return;
 76                 }
 77             }
 78         }
 79     }
 80 }
 81 void solve()
 82 {
 83     int n, m;
 84     while(scanf("%d%d", &m, &n) == 2 && n != -1 && m != -1) {
 85         init();
 86         int x, y, d, t;
 87         for(int i = 0; i < m; i++){
 88             scanf("%d%d%d%d", &x, &y, &d, &t);
 89             build_wall(x, y, d, t);
 90         }
 91 
 92         for(int i = 0; i < n; i++){
 93             scanf("%d%d%d", &x, &y, &d);
 94             door(x, y, d);
 95         }
 96         double f1, f2;
 97         scanf("%lf%lf", &f1, &f2);
 98         node nd; nd.x = 2*(int)floor(f1); nd.y = 2*(int)floor(f2);
 99         if(checkBound(nd.x, nd.y)){
100             arr[nd.x][nd.y] = 4;
101             findNemo();
102             if(minStep == 160000) printf("-1\n");
103             else printf("%d\n", minStep);
104         }
105         else printf("0\n");
106     }
107 }
108 int main()
109 {
110     solve();
111     return 0;
112 }      

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转载于:https://www.cnblogs.com/ZiningTang/p/5256143.html