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
#include<cstdio>
#include<queue>
#include<cstring>
using namespace std;
struct dt{int s,m,n,t;};
int s,m,n;
bool v[][][];
int bfs(){
memset(v,,sizeof(v));
v[s][][]=;
dt tmp,o;tmp.s=s,tmp.m=,tmp.n=,tmp.t=;
queue<dt>Q;Q.push(tmp);
while(!Q.empty()){
o=Q.front();Q.pop();
if((o.s==o.m&&!o.n)||(o.s==o.n&&!o.m)||(o.n==o.m&&!o.s))return o.t;
if(o.s){
if(o.m<m){
if(o.s+o.m>=m){
tmp.m=m,tmp.s=o.s+o.m-m,tmp.n=o.n,tmp.t=o.t+;
if(!v[tmp.s][tmp.m][tmp.n]){Q.push(tmp);v[tmp.s][tmp.m][tmp.n]=;}
}else{
tmp.m=o.m+o.s,tmp.s=,tmp.n=o.n,tmp.t=o.t+;
if(!v[tmp.s][tmp.m][tmp.n]){Q.push(tmp);v[tmp.s][tmp.m][tmp.n]=;}
}
}
if(o.n<n){
if(o.s+o.n>=n){
tmp.n=n,tmp.s=o.s+o.n-n,tmp.m=o.m,tmp.t=o.t+;
if(!v[tmp.s][tmp.m][tmp.n]){Q.push(tmp);v[tmp.s][tmp.m][tmp.n]=;}
}else{
tmp.n=o.n+o.s,tmp.s=,tmp.m=o.m,tmp.t=o.t+;
if(!v[tmp.s][tmp.m][tmp.n]){Q.push(tmp);v[tmp.s][tmp.m][tmp.n]=;}
}
}
}
if(o.m){
if(o.s<s){
if(o.s+o.m>=s){
tmp.s=s,tmp.m=o.m+o.s-s,tmp.n=o.n,tmp.t=o.t+;
if(!v[tmp.s][tmp.m][tmp.n]){Q.push(tmp);v[tmp.s][tmp.m][tmp.n]=;}
}else{
tmp.s=o.s+o.m,tmp.m=,tmp.n=o.n,tmp.t=o.t+;
if(!v[tmp.s][tmp.m][tmp.n]){Q.push(tmp);v[tmp.s][tmp.m][tmp.n]=;}
}
}
if(o.n<n){
if(o.m+o.n>=n){
tmp.n=n,tmp.m=o.m+o.n-n,tmp.s=o.s,tmp.t=o.t+;
if(!v[tmp.s][tmp.m][tmp.n]){Q.push(tmp);v[tmp.s][tmp.m][tmp.n]=;}
}else{
tmp.n=o.n+o.m,tmp.m=,tmp.s=o.s,tmp.t=o.t+;
if(!v[tmp.s][tmp.m][tmp.n]){Q.push(tmp);v[tmp.s][tmp.m][tmp.n]=;}
}
}
}
if(o.n){
if(o.m<m){
if(o.n+o.m>=m){
tmp.m=m,tmp.n=o.n+o.m-m,tmp.s=o.s,tmp.t=o.t+;
if(!v[tmp.s][tmp.m][tmp.n]){Q.push(tmp);v[tmp.s][tmp.m][tmp.n]=;}
}else{
tmp.m=o.m+o.n,tmp.n=,tmp.s=o.s,tmp.t=o.t+;
if(!v[tmp.s][tmp.m][tmp.n]){Q.push(tmp);v[tmp.s][tmp.m][tmp.n]=;}
}
}
if(o.s<s){
if(o.n+o.s>=s){
tmp.s=s,tmp.n=o.n+o.s-s,tmp.m=o.m,tmp.t=o.t+;
if(!v[tmp.s][tmp.m][tmp.n]){Q.push(tmp);v[tmp.s][tmp.m][tmp.n]=;}
}else{
tmp.s=o.s+o.n,tmp.n=,tmp.m=o.m,tmp.t=o.t+;
if(!v[tmp.s][tmp.m][tmp.n]){Q.push(tmp);v[tmp.s][tmp.m][tmp.n]=;}
}
}
}
}
return -;
}
int main(){
while(~scanf("%d%d%d",&s,&m,&n),s+n+m){
if(s%){puts("NO");continue;}
int ans=bfs();
if(ans==-)puts("NO");
else printf("%d\n",ans);
}
return ;
}