题目连接：http://acm.hdu.edu.cn/showproblem.php?pid=1495
题意：不解释
题解：BFS模拟，不过要细心，把所有情况都列举出来，开一个数组记录状态，代码有点长，比较重复，尝试优化了一下，不过WA了
1 #include<cstdio> 2 #include<queue> 3 #include<cstring> 4 using namespace std; 5 struct dt{int s,m,n,t;}; 6 int s,m,n; 7 bool v[101][101][101]; 8 int bfs(){ 9 memset(v,0,sizeof(v)); 10 v[s][0][0]=1; 11 dt tmp,o;tmp.s=s,tmp.m=0,tmp.n=0,tmp.t=0; 12 queue<dt>Q;Q.push(tmp); 13 while(!Q.empty()){ 14 o=Q.front();Q.pop(); 15 if((o.s==o.m&&!o.n)||(o.s==o.n&&!o.m)||(o.n==o.m&&!o.s))return o.t; 16 if(o.s){ 17 if(o.m<m){ 18 if(o.s+o.m>=m){ 19 tmp.m=m,tmp.s=o.s+o.m-m,tmp.n=o.n,tmp.t=o.t+1; 20 if(!v[tmp.s][tmp.m][tmp.n]){Q.push(tmp);v[tmp.s][tmp.m][tmp.n]=1;} 21 }else{ 22 tmp.m=o.m+o.s,tmp.s=0,tmp.n=o.n,tmp.t=o.t+1; 23 if(!v[tmp.s][tmp.m][tmp.n]){Q.push(tmp);v[tmp.s][tmp.m][tmp.n]=1;} 24 } 25 } 26 if(o.n<n){ 27 if(o.s+o.n>=n){ 28 tmp.n=n,tmp.s=o.s+o.n-n,tmp.m=o.m,tmp.t=o.t+1; 29 if(!v[tmp.s][tmp.m][tmp.n]){Q.push(tmp);v[tmp.s][tmp.m][tmp.n]=1;} 30 }else{ 31 tmp.n=o.n+o.s,tmp.s=0,tmp.m=o.m,tmp.t=o.t+1; 32 if(!v[tmp.s][tmp.m][tmp.n]){Q.push(tmp);v[tmp.s][tmp.m][tmp.n]=1;} 33 } 34 } 35 } 36 if(o.m){ 37 if(o.s<s){ 38 if(o.s+o.m>=s){ 39 tmp.s=s,tmp.m=o.m+o.s-s,tmp.n=o.n,tmp.t=o.t+1; 40 if(!v[tmp.s][tmp.m][tmp.n]){Q.push(tmp);v[tmp.s][tmp.m][tmp.n]=1;} 41 }else{ 42 tmp.s=o.s+o.m,tmp.m=0,tmp.n=o.n,tmp.t=o.t+1; 43 if(!v[tmp.s][tmp.m][tmp.n]){Q.push(tmp);v[tmp.s][tmp.m][tmp.n]=1;} 44 } 45 } 46 if(o.n<n){ 47 if(o.m+o.n>=n){ 48 tmp.n=n,tmp.m=o.m+o.n-n,tmp.s=o.s,tmp.t=o.t+1; 49 if(!v[tmp.s][tmp.m][tmp.n]){Q.push(tmp);v[tmp.s][tmp.m][tmp.n]=1;} 50 }else{ 51 tmp.n=o.n+o.m,tmp.m=0,tmp.s=o.s,tmp.t=o.t+1; 52 if(!v[tmp.s][tmp.m][tmp.n]){Q.push(tmp);v[tmp.s][tmp.m][tmp.n]=1;} 53 } 54 } 55 } 56 if(o.n){ 57 if(o.m<m){ 58 if(o.n+o.m>=m){ 59 tmp.m=m,tmp.n=o.n+o.m-m,tmp.s=o.s,tmp.t=o.t+1; 60 if(!v[tmp.s][tmp.m][tmp.n]){Q.push(tmp);v[tmp.s][tmp.m][tmp.n]=1;} 61 }else{ 62 tmp.m=o.m+o.n,tmp.n=0,tmp.s=o.s,tmp.t=o.t+1; 63 if(!v[tmp.s][tmp.m][tmp.n]){Q.push(tmp);v[tmp.s][tmp.m][tmp.n]=1;} 64 } 65 } 66 if(o.s<s){ 67 if(o.n+o.s>=s){ 68 tmp.s=s,tmp.n=o.n+o.s-s,tmp.m=o.m,tmp.t=o.t+1; 69 if(!v[tmp.s][tmp.m][tmp.n]){Q.push(tmp);v[tmp.s][tmp.m][tmp.n]=1;} 70 }else{ 71 tmp.s=o.s+o.n,tmp.n=0,tmp.m=o.m,tmp.t=o.t+1; 72 if(!v[tmp.s][tmp.m][tmp.n]){Q.push(tmp);v[tmp.s][tmp.m][tmp.n]=1;} 73 } 74 } 75 } 76 } 77 return -1; 78 } 79 int main(){ 80 while(~scanf("%d%d%d",&s,&m,&n),s+n+m){ 81 if(s%2){puts("NO");continue;} 82 int ans=bfs(); 83 if(ans==-1)puts("NO"); 84 else printf("%d ",ans); 85 } 86 return 0; 87 }