HDU 1495 - 非常可乐

可乐倒来倒去的问题，BFS

 

  1 #include <iostream>
  2 #include <queue>
  3 #include <cstring>
  4 using namespace std;
  5 struct node{
  6     int s,n,m,t;
  7 }now,nxt;
  8 int s,n,m;
  9 queue<node> q;
 10 int flag[105][105][105];
 11 bool check(node a)
 12 {
 13     return (a.s==a.n&&a.m==0) || (a.s==a.m&&a.n==0) || (a.m==a.n&&a.s==0);
 14 }
 15 int bfs()
 16 {
 17     while(!q.empty()) q.pop();
 18     memset(flag,0,sizeof(flag));
 19     now.s=s; 
 20     now.t=now.n=now.m=0;
 21     q.push(now);    flag[s][0][0]=1;
 22     while(!q.empty())
 23     {
 24         now=q.front(); q.pop();
 25         if(check(now)) return now.t;
 26         nxt.t=now.t+1;
 27         if(now.s<s){//开始强行判断，基本整段复制改一改 
 28             if(now.m>0){
 29                 if(now.m>s-now.s){
 30                     nxt.s=s;
 31                     nxt.m=now.m-(s-now.s);
 32                     nxt.n=now.n;
 33                 } else {
 34                     nxt.s=now.s+now.m;
 35                     nxt.m=0;
 36                     nxt.n=now.n;        
 37                 }
 38                 if(!flag[nxt.s][nxt.m][nxt.n]){
 39                     q.push(nxt); flag[nxt.s][nxt.m][nxt.n]=1;
 40                 } 
 41             }
 42             if(now.n>0){
 43                 if(now.n>s-now.s){
 44                     nxt.s=s;
 45                     nxt.n=now.n-(s-now.s);
 46                     nxt.m=now.m;
 47                 } else {
 48                     nxt.s=now.s+now.n;
 49                     nxt.n=0;
 50                     nxt.m=now.m;        
 51                 }
 52                 if(!flag[nxt.s][nxt.m][nxt.n]){
 53                     q.push(nxt); flag[nxt.s][nxt.m][nxt.n]=1;
 54                 }                 
 55             }
 56         }
 57         if(now.m<m){
 58             if(now.s>0){
 59                 if(now.s>m-now.m){
 60                     nxt.m=m;
 61                     nxt.s=now.s-(m-now.m);
 62                     nxt.n=now.n;
 63                 } else {
 64                     nxt.m=now.m+now.s;
 65                     nxt.s=0;
 66                     nxt.n=now.n;        
 67                 }
 68                 if(!flag[nxt.s][nxt.m][nxt.n]){
 69                     q.push(nxt); flag[nxt.s][nxt.m][nxt.n]=1;
 70                 } 
 71             }
 72             if(now.n>0){
 73                 if(now.n>m-now.m){
 74                     nxt.m=m;
 75                     nxt.n=now.n-(m-now.m);
 76                     nxt.s=now.s;
 77                 } else {
 78                     nxt.m=now.m+now.n;
 79                     nxt.n=0;
 80                     nxt.s=now.s;        
 81                 }
 82                 if(!flag[nxt.s][nxt.m][nxt.n]){
 83                     q.push(nxt); flag[nxt.s][nxt.m][nxt.n]=1;
 84                 }
 85             }            
 86         }
 87         if(now.n<n){
 88             if(now.s>0){
 89                 if(now.s>n-now.n){
 90                     nxt.n=n;
 91                     nxt.s=now.s-(n-now.n);
 92                     nxt.m=now.m;
 93                 } else {
 94                     nxt.n=now.n+now.s;
 95                     nxt.s=0;
 96                     nxt.m=now.m;        
 97                 }
 98                 if(!flag[nxt.s][nxt.m][nxt.n]){
 99                     q.push(nxt); flag[nxt.s][nxt.m][nxt.n]=1;
100                 } 
101             }
102             if(now.m>0){
103                 if(now.m>n-now.n){
104                     nxt.n=n;
105                     nxt.m=now.m-(n-now.n);
106                     nxt.s=now.s;
107                 } else {
108                     nxt.n=now.n+now.m;
109                     nxt.m=0;
110                     nxt.s=now.s;        
111                 }
112                 if(!flag[nxt.s][nxt.m][nxt.n]){
113                     q.push(nxt); flag[nxt.s][nxt.m][nxt.n]=1;
114                 }
115             }            
116         }
117     }
118     return -1;
119 }
120 int main()
121 {
122     while(~scanf("%d%d%d",&s,&n,&m),(n+m+s))
123     {
124         if(m<n) swap(m,n);
125         int ans=bfs();
126         if(ans==-1) puts("NO");
127         else printf("%d\n",ans);
128     }
129 }

 

posted @ 2016-04-26 19:27  nicetomeetu  阅读(151)  评论(0)  编辑  收藏  举报