poj2049(bfs) Finding Nemo
2013-07-13 10:38
92 查看
Finding Nemo
DescriptionNemo is a naughty boy. One day he went into the deep sea all by himself. Unfortunately, he became lost and couldn't find his way home. Therefore, he sent a signal to his father, Marlin, to ask for help. After checking the map, Marlin found that the sea is like a labyrinth with walls and doors. All the walls are parallel to the X-axis or to the Y-axis. The thickness of the walls are assumed to be zero. All the doors are opened on the walls and have a length of 1. Marlin cannot go through a wall unless there is a door on the wall. Because going through a door is dangerous (there may be some virulent medusas near the doors), Marlin wants to go through as few doors as he could to find Nemo. Figure-1 shows an example of the labyrinth and the path Marlin went through to find Nemo.
We assume Marlin's initial position is at (0, 0). Given the position of Nemo and the configuration of walls and doors, please write a program to calculate the minimum number of doors Marlin has to go through in order to reach Nemo.InputThe input consists of several test cases. Each test case is started by two non-negative integers M and N. M represents the number of walls in the labyrinth and N represents the number of doors. Then follow M lines, each containing four integers that describe a wall in the following format: x y d t (x, y) indicates the lower-left point of the wall, d is the direction of the wall -- 0 means it's parallel to the X-axis and 1 means that it's parallel to the Y-axis, and t gives the length of the wall. The coordinates of two ends of any wall will be in the range of [1,199]. Then there are N lines that give the description of the doors: x y d x, y, d have the same meaning as the walls. As the doors have fixed length of 1, t is omitted. The last line of each case contains two positive float numbers: f1 f2 (f1, f2) gives the position of Nemo. And it will not lie within any wall or door. A test case of M = -1 and N = -1 indicates the end of input, and should not be processed.OutputFor each test case, in a separate line, please output the minimum number of doors Marlin has to go through in order to rescue his son. If he can't reach Nemo, output -1.Sample Input
Sample Output
Source
Beijing 2004
我被这道题深深地坑了,WA了一天,然后每天还拿出来看看,希望发现什么错误,结果今天李成明学长给我看了一遍也没发现什么问题,无奈之下就提交了,用了GCC结果AC了。。。汗,耽误学长那么长时间,要重重的感谢学长啊!!!
说说我的思路吧,把它看成网格,每个网格四条边,四个方向变量,0123分别表示上左下右四个方向。主要就是把题目数据转化成我们熟知的那种迷宫就好了,然后就是bfs就行了
Memory: 1896 KBTime: 47 MS
Language: GCCResult: Accepted
Time Limit: 2000MS | Memory Limit: 30000K | |
Total Submissions: 6864 | Accepted: 1569 |
We assume Marlin's initial position is at (0, 0). Given the position of Nemo and the configuration of walls and doors, please write a program to calculate the minimum number of doors Marlin has to go through in order to reach Nemo.InputThe input consists of several test cases. Each test case is started by two non-negative integers M and N. M represents the number of walls in the labyrinth and N represents the number of doors. Then follow M lines, each containing four integers that describe a wall in the following format: x y d t (x, y) indicates the lower-left point of the wall, d is the direction of the wall -- 0 means it's parallel to the X-axis and 1 means that it's parallel to the Y-axis, and t gives the length of the wall. The coordinates of two ends of any wall will be in the range of [1,199]. Then there are N lines that give the description of the doors: x y d x, y, d have the same meaning as the walls. As the doors have fixed length of 1, t is omitted. The last line of each case contains two positive float numbers: f1 f2 (f1, f2) gives the position of Nemo. And it will not lie within any wall or door. A test case of M = -1 and N = -1 indicates the end of input, and should not be processed.OutputFor each test case, in a separate line, please output the minimum number of doors Marlin has to go through in order to rescue his son. If he can't reach Nemo, output -1.Sample Input
8 9 1 1 1 3 2 1 1 3 3 1 1 3 4 1 1 3 1 1 0 3 1 2 0 3 1 3 0 3 1 4 0 3 2 1 1 2 2 1 2 3 1 3 1 1 3 2 1 3 3 1 1 2 0 3 3 0 4 3 1 1.5 1.5 4 0 1 1 0 1 1 1 1 1 2 1 1 1 1 2 0 1 1.5 1.7 -1 -1
Sample Output
5 -1
Source
Beijing 2004
我被这道题深深地坑了,WA了一天,然后每天还拿出来看看,希望发现什么错误,结果今天李成明学长给我看了一遍也没发现什么问题,无奈之下就提交了,用了GCC结果AC了。。。汗,耽误学长那么长时间,要重重的感谢学长啊!!!
说说我的思路吧,把它看成网格,每个网格四条边,四个方向变量,0123分别表示上左下右四个方向。主要就是把题目数据转化成我们熟知的那种迷宫就好了,然后就是bfs就行了
Memory: 1896 KBTime: 47 MS
Language: GCCResult: Accepted
#include<stdio.h> #include<string.h> struct ste{ int x,y,s; }r[1000000]; int m,n,map[210][210][4],map2[210][210][4],minx,miny,maxx,maxy,dx,dy,min;//0表示最上方,逆时针 void bfs(int x,int y,int d) { int i,j,t=0,w=1; r[0].x=x; r[0].y=y; r[0].s=0; if(map[x][y][d]==1) r[0].s++; memset(map2,0,sizeof(map2)); map2[x][y][d]=1; while(t<w) { if(r[t].x<minx||r[t].x>maxx||r[t].y>maxy||r[t].y<miny) { t++; continue; } if(r[t].x==dx&&r[t].y==dy) { if(min>r[t].s) min=r[t].s; t++; continue; } if(r[t].s>=min) { t++; continue; } for(i=0;i<4;i++) { //printf("i%dmap2[r[t].x][r[t].y][i]%dx%dy%ds%d\n",i,map2[r[t].x][r[t].y][i],r[t].x,r[t].y,r[t].s); if(map[r[t].x][r[t].y][i]!=2&&map2[r[t].x][r[t].y][i]==0) {//printf("2x%dy%ds%di%d\n",r[t].x,r[t].y,r[t].s,i); switch(i) { case 0:if(r[t].x>=minx&&r[t].x<=maxx&&r[t].y>=miny&&r[t].y<maxy) { r[w].x=r[t].x; r[w].y=r[t].y+1; r[w].s=r[t].s; if(map[r[t].x][r[t].y][i]==1) r[w].s++; w++; map2[r[t].x][r[t].y][i]=1; map2[r[t].x][r[t].y+1][2]=1; //printf("0x%dy%ds%d\n",r[t].x,r[t].y+1,r[w-1].s); } break; case 1:if(r[t].x>minx&&r[t].x<=maxx&&r[t].y>=miny&&r[t].y<=maxy) { r[w].x=r[t].x-1; r[w].y=r[t].y; r[w].s=r[t].s; if(map[r[t].x][r[t].y][i]==1) r[w].s++; w++; //printf("s-%d-",r[w-1].s); map2[r[t].x][r[t].y][i]=1; map2[r[t].x-1][r[t].y][3]=1;//printf("1x%dy%ds%d\n",r[t].x-1,r[t].y,r[w-1].s); } break; case 2:if(r[t].x>=minx&&r[t].x<=maxx&&r[t].y>miny&&r[t].y<=maxy) {//printf("21x%dy%ds%d\n",r[t].x,r[t].y-1,r[t].s); r[w].x=r[t].x; r[w].y=r[t].y-1; r[w].s=r[t].s; if(map[r[t].x][r[t].y][i]==1) r[w].s++; w++; map2[r[t].x][r[t].y][i]=1; map2[r[t].x][r[t].y-1][0]=1; } break; case 3:if(r[t].x>=minx&&r[t].x<maxx&&r[t].y>=miny&&r[t].y<=maxy) { r[w].x=r[t].x+1; r[w].y=r[t].y; r[w].s=r[t].s; if(map[r[t].x][r[t].y][i]==1) r[w].s++; w++; map2[r[t].x][r[t].y][i]=1; map2[r[t].x+1][r[t].y][1]=1;//printf("3x%dy%ds%d\n",r[t].x+1,r[t].y,r[w-1].s); } break; } } } t++; } } int main() { int i,j,t,d,x,y; double a,b; while(1) { scanf("%d%d",&m,&n); min=1000000; if(n==-1&&m==-1) break; minx=miny=3002; maxx=maxy=-100; memset(map,0,sizeof(map)); for(i=0;i<m;i++) { scanf("%d%d%d%d",&x,&y,&d,&t); if(minx>x) minx=x; if(miny>y) miny=y; if(maxy<y) maxy=y; if(maxx<x) maxx=x; if(d==1) { for(j=0;j<t;j++) { map[x][y+j][1]=2; map[x-1][y+j][3]=2; } } else { for(j=0;j<t;j++) { map[x+j][y][2]=2;//2表示墙 map[x+j][y-1][0]=2; } } } for(i=0;i<n;i++) { scanf("%d%d%d",&x,&y,&d); if(minx>x) minx=x; if(miny>y) miny=y; if(maxy<y) maxy=y; if(maxx<x) maxx=x; if(d==1) { map[x][y][1]=1;//1表示门 map[x-1][y][3]=1; } else { map[x][y][2]=1; map[x][y-1][0]=1; } } maxx--; maxy--; scanf("%lf%lf",&a,&b); dx=a; dy=b; //printf("%d-%d\n",dx,dy); if(dx<minx||dx>maxx||dy<miny||dy>maxy) { printf("0\n"); continue; } for(j=minx;j<=maxx;j++)//上方 { if(map[j][maxy][0]!=2) bfs(j,maxy,0); } for(j=miny;j<=maxy;j++)//左方可进 { if(map[minx][j][1]!=2) bfs(minx,j,1); } for(j=minx;j<=maxx;j++)//下方 { if(map[j][miny][2]!=2) bfs(j,miny,2); } for(j=miny;j<=maxy;j++)//右方 { if(map[maxx][j][3]!=2) bfs(maxx,j,3); } //printf("minx%dminy%dmaxx%dmaxy%d\n",minx,miny,maxx,maxy); if(min!=1000000) printf("%d\n",min); else printf("-1\n"); } return 0; }
相关文章推荐
- 【bfs+优先队列】POJ2049-Finding Nemo
- poj2049 Finding Nemo BFS
- poj2049 Finding Nemo(优先队列BFS)
- POJ 2049 Finding Nemo 网格bfs
- poj-2049 Finding Nemo-BFS
- poj2049--Finding Nemo
- POJ 2049 Finding Nemo(三维BFS)
- POJ 2049— Finding Nemo(三维BFS)10/200
- poj-2049-Finding Nemo-BFS
- POJ训练计划2049_Finding Nemo(建图/BFS)
- POJ 2049-Finding Nemo(三维bfs解决类迷宫问题)
- poj 2049 Finding Nemo(bfs)
- POJ 2049 Finding Nemo BFS 三维数组存状态, 优先队列优化时间与空间
- poj2049——Finding Nemo(bfs)
- poj2049Finding Nemo
- Finding Nemo POJ 2049(bfs+dp思想)
- poj2049Finding Nemo(BFS+优先队列)
- poj 2049 Finding Nemo(优先队列+bfs)
- POJ 2049 Finding Nemo (网格中的BFS)
- 【POJ】 2049 Finding Nemo BFS