HDU 1495 非常可乐 BFS

#include <iostream>
#include <cstring>
#include <cstdio>
#include <algorithm>
#include <queue>
#include <vector>
#include <iomanip>
#include <math.h>
#include <map>
using namespace std;
#define FIN     freopen("input.txt","r",stdin);
#define FOUT    freopen("output.txt","w",stdout);
#define INF     0x3f3f3f3f
#define INFLL   0x3f3f3f3f3f3f3f
#define lson    l,m,rt<<1
#define rson    m+1,r,rt<<1|1
typedef long long LL;

struct node{
   int ml[3];
   int times;
};

int cola[3];
int vis[105][105][105];
double ave;

queue<node>q;

int bfs(int x,int y,int z){
    while(!q.empty())  {q.pop();}
    node fir;
    fir.ml[0]=x;
    fir.ml[1]=y;
    fir.ml[2]=z;
    fir.times=0;
    q.push(fir);
    while(!q.empty()){
        node p=q.front();
        q.pop();
        for(int i=0;i<3;i++)
            for(int j=0;j<3;j++){
                if(i==j)  continue;

                node p1;
                if(p.ml[i]+p.ml[j]<cola[j]){
                    p1.ml[i]=0;
                    p1.ml[j]=p.ml[i]+p.ml[j];
                }else{
                    p1.ml[i]=p.ml[i]+p.ml[j]-cola[j];
                    p1.ml[j]=cola[j];
                }
                for(int ii=0;ii<3;ii++){
                    if(ii==i||ii==j)  continue;
                    p1.ml[ii]=p.ml[ii];
                }

                if(vis[p1.ml[0]][p1.ml[1]][p1.ml[2]])  continue;

                vis[p1.ml[0]][p1.ml[1]][p1.ml[2]]=1;
                p1.times=p.times+1;

                q.push(p1);
                if((p1.ml[0]==ave&&p1.ml[0]==p1.ml[1])||(p1.ml[0]==ave&&p1.ml[0]==p1.ml[2])||(p1.ml[1]==ave&&p1.ml[1]==p1.ml[2])){
                    printf("%d\n",p1.times);
                    return 0;

                }

            }
    }
    printf("NO\n");

}


int main()
{
    //FIN
    int S,N,M;
    while(~scanf("%d%d%d",&S,&N,&M))
    {
        if(S==0&&N==0&&M==0)  break;
        memset(vis,0,sizeof(vis));
        cola[0]=S;
        cola[1]=N;
        cola[2]=M;
        ave=S/2.0;        //这里一定要/2.0
        bfs(S,0,0);
    }
}