321UVA【错误原因】怕黑先生别墅找卧室

正确：

#include<stdio.h>#include<string.h>//1:“move from one room to another”//2:“switch on a light” //3:“switch off a light” const int maxstate=300000;    //30000const int maxhash=30000;typedef int State[10];int op[maxstate];int fa[maxstate];int step[maxstate];int pos[maxstate];State que[maxstate];int r,d,s;bool door[15][15];bool swi[15][15];State goal,ini;int head[maxhash];int next[maxstate];int hashv(State& s,int pos){int v=0;for(int i=r-1;i>=0;i--){v=v*2+s[i];}v=v*2+pos;return v%maxhash;}bool tryinsert(int id){int h=hashv(que[id],pos[id]);int u=head[h];while(u){if(0==memcmp(&que[id],&que[u],sizeof(State))&&pos[id]==pos[u])return false;u=next[u];}next[id]=head[h];head[h]=id;return true;}int bfs(){memset(head,0,sizeof(head));int front,rear;front=rear=1;op[rear]=0;fa[rear]=1;step[rear]=0;pos[rear]=0;memcpy(&que[rear],&ini,sizeof(State));rear++;while(front<rear){State& s=que[front];int spos=pos[front];if(spos==r-1 && 0==memcmp(&que[front],&goal,sizeof(State)) )return front;//move to another lighted roomfor(int i=0;i<r;i++){if(door[spos][i]&&s[i]){op[rear]=10+i;fa[rear]=front;step[rear]=step[front]+1;pos[rear]=i;memcpy(&que[rear],&s,sizeof(State));if(tryinsert(rear)){rear++;}}}//switch light on/offfor(int i=0;i<r;i++){if(swi[spos][i])  //CRASH!{if(i==spos) continue;if(s[i]==0) //on:2op[rear]=20+i;elseop[rear]=30+i;fa[rear]=front;step[rear]=step[front]+1;pos[rear]=spos;memcpy(&que[rear],&s,sizeof(State));que[rear][i] = (!que[rear][i]);if(tryinsert(rear)){rear++;}}}front++;}return -1;}void print(int id){if(fa[id]!=id){print(fa[id]);int choose=op[id]/10;switch(choose){case 1:printf("- Move to room %d.\n",op[id]%10+1);break;case 2:printf("- Switch on light in room %d.\n",op[id]%10+1);break;case 3:printf("- Switch off light in room %d.\n",op[id]%10+1);break;}}}int main(){//freopen("input.txt","r",stdin);freopen("out.txt","w",stdout);int numcase=1;int u,v;while(scanf("%d%d%d",&r,&d,&s)==3){if(!r&&!d&&!s) break;memset(door,false,sizeof(door));memset(swi,false,sizeof(swi));for(int i=0;i<d;i++){scanf("%d%d",&u,&v);door[u-1][v-1]=door[v-1][u-1]=true;}for(int i=0;i<s;i++){scanf("%d%d",&u,&v);swi[u-1][v-1]=true;}memset(goal,0,sizeof(goal));memset(ini,0,sizeof(ini));goal[r-1]=1;ini[0]=1;int res = bfs();printf("Villa #%d\n",numcase++);/* adding this is also rightif(r==1){printf("The problem can be solved in %d steps:\n",0);putchar(10);continue;}*/if(res==-1)printf("The problem cannot be solved.\n");else{printf("The problem can be solved in %d steps:\n",step[res]);print(res);}putchar(10);}}

错误：

#include<stdio.h>#include<string.h>//1:“move from one room to another”//2:“switch on a light” //3:“switch off a light” const int maxstate=30000;const int maxhash=30000;typedef int State[10];int op[maxstate];int fa[maxstate];int step[maxstate];int pos[maxstate];State que[maxstate];int r,d,s;bool door[15][15];bool swi[15][15];State goal,ini;int head[maxhash];int next[maxstate];int hashv(State& s,int pos){int v=0;for(int i=0;i<r;i++){v=v*2+s[i];}v=v+pos*3;return v%maxhash;}bool tryinsert(int id){int h=hashv(que[id],pos[id]);int u=head[h];while(u){if(0==memcmp(&que[id],&que[u],sizeof(State))&&pos[id]==pos[u])return false;u=next[u];}next[id]=head[h];head[h]=id;return true;}int bfs(){memset(head,0,sizeof(head));int front,rear;front=rear=1;op[rear]=1;fa[rear]=1;step[rear]=0;pos[rear]=0;memcpy(&que[rear],&ini,sizeof(State));rear++;while(front<rear){State& s=que[front];int spos=pos[front];if(spos==r-1 && 0==memcmp(&que[front],&goal,sizeof(State)) )return front;//move to another lighted roomfor(int i=0;i<r;i++){if(door[spos][i]&&s[i]){op[rear]=10+i;fa[rear]=front;step[rear]=step[front]+1;pos[rear]=i;memcpy(&que[rear],&s,sizeof(State));if(tryinsert(rear)){rear++;}}}//switch light on/offfor(int i=0;i<r;i++){if(swi[spos][i])  //CRASH!{if(i==spos) continue;if(s[i]==0) //on:2op[rear]=20+i;elseop[rear]=30+i;fa[rear]=front;step[rear]=step[front]+1;pos[rear]=spos;memcpy(&que[rear],&s,sizeof(State));que[rear][i] = (!que[rear][i]);if(tryinsert(rear)){rear++;}}}front++;}return -1;}void print(int id){if(fa[id]!=id){print(fa[id]);int choose=op[id]/10;switch(choose){case 1:printf("- Move to room %d.\n",op[id]%10+1);break;case 2:printf("- Switch on light in room %d.\n",op[id]%10+1);break;case 3:printf("- Switch off light in room %d.\n",op[id]%10+1);break;}}}int main(){//freopen("input.txt","r",stdin);freopen("out.txt","w",stdout);int numcase=1;int u,v;while(scanf("%d%d%d",&r,&d,&s)==3){memset(door,false,sizeof(door));memset(swi,false,sizeof(swi));if(!r&&!d&&!s) break;for(int i=0;i<d;i++){scanf("%d%d",&u,&v);door[u-1][v-1]=door[v-1][u-1]=true;}for(int i=0;i<s;i++){scanf("%d%d",&u,&v);swi[u-1][v-1]=true;}for(int i=0;i<r;i++){if(i==0){goal[i]=0;ini[i]=1;continue;}if(i==r-1){goal[i]=1;ini[i]=0;continue;}goal[i]=0;ini[i]=0;}int res = bfs();printf("Villa #%d\n",numcase++);if(r==1){printf("The problem can be solved in %d steps:\n",0);putchar(10);continue;}if(res==-1)printf("The problem cannot be solved.\n");else{printf("The problem can be solved in %d steps:\n",step[res]);print(res);}putchar(10);}}