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[101][101][101]; int bfs(){ memset(v,0,sizeof(v)); v[s][0][0]=1; dt tmp,o;tmp.s=s,tmp.m=0,tmp.n=0,tmp.t=0; 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+1; if(!v[tmp.s][tmp.m][tmp.n]){Q.push(tmp);v[tmp.s][tmp.m][tmp.n]=1;} }else{ tmp.m=o.m+o.s,tmp.s=0,tmp.n=o.n,tmp.t=o.t+1; if(!v[tmp.s][tmp.m][tmp.n]){Q.push(tmp);v[tmp.s][tmp.m][tmp.n]=1;} } } 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+1; if(!v[tmp.s][tmp.m][tmp.n]){Q.push(tmp);v[tmp.s][tmp.m][tmp.n]=1;} }else{ tmp.n=o.n+o.s,tmp.s=0,tmp.m=o.m,tmp.t=o.t+1; if(!v[tmp.s][tmp.m][tmp.n]){Q.push(tmp);v[tmp.s][tmp.m][tmp.n]=1;} } } } 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+1; if(!v[tmp.s][tmp.m][tmp.n]){Q.push(tmp);v[tmp.s][tmp.m][tmp.n]=1;} }else{ tmp.s=o.s+o.m,tmp.m=0,tmp.n=o.n,tmp.t=o.t+1; if(!v[tmp.s][tmp.m][tmp.n]){Q.push(tmp);v[tmp.s][tmp.m][tmp.n]=1;} } } 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+1; if(!v[tmp.s][tmp.m][tmp.n]){Q.push(tmp);v[tmp.s][tmp.m][tmp.n]=1;} }else{ tmp.n=o.n+o.m,tmp.m=0,tmp.s=o.s,tmp.t=o.t+1; if(!v[tmp.s][tmp.m][tmp.n]){Q.push(tmp);v[tmp.s][tmp.m][tmp.n]=1;} } } } 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+1; if(!v[tmp.s][tmp.m][tmp.n]){Q.push(tmp);v[tmp.s][tmp.m][tmp.n]=1;} }else{ tmp.m=o.m+o.n,tmp.n=0,tmp.s=o.s,tmp.t=o.t+1; if(!v[tmp.s][tmp.m][tmp.n]){Q.push(tmp);v[tmp.s][tmp.m][tmp.n]=1;} } } 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+1; if(!v[tmp.s][tmp.m][tmp.n]){Q.push(tmp);v[tmp.s][tmp.m][tmp.n]=1;} }else{ tmp.s=o.s+o.n,tmp.n=0,tmp.m=o.m,tmp.t=o.t+1; if(!v[tmp.s][tmp.m][tmp.n]){Q.push(tmp);v[tmp.s][tmp.m][tmp.n]=1;} } } } } return -1; } int main(){ while(~scanf("%d%d%d",&s,&m,&n),s+n+m){ if(s%2){puts("NO");continue;} int ans=bfs(); if(ans==-1)puts("NO"); else printf("%d\n",ans); } return 0; }