hdoj1495简单BFS

来源：互联网发布：数据库事务特性老婆编辑：程序博客网时间：2024/06/13 23:18
#include <stdio.h>#include <string.h>#include <math.h>#include <algorithm>#include <iostream>using namespace std;#define LL __int64#define mod 9973#define N 100010int n,m,s;bool vis[102][110][110];struct asd{    int cup1;    int cup2;    int cup3;    int step;};asd q[N];int head,tail;void bfs(){    memset(vis,0,sizeof(vis));    head=0;tail=1;    q[head].cup1=s;    q[head].cup2=0;    q[head].cup3=0;    q[head].step=0;    vis[s][0][0]=1;    int x,y,z;    while(head<tail)    {        int a=q[head].cup1;        int b=q[head].cup2;        int c=q[head].cup3;        if(a==b&&a==s/2)        {            printf("%d\n",q[head].step);            return;        }        //cup1->cup2|cup1->cup3|先cup1->cup2后cup1->cup3         if(a>0)        {            //cup1->cup2只能倒满，或者倒不满            //不会出现倒不满的现象，只会倒不倒；            x=a-(n-b);            y=n;            z=c;            if(!vis[x][y][z])            {                vis[x][y][z]=1;                q[tail].cup1=x;                q[tail].cup2=y;                q[tail].cup3=z;                q[tail].step=q[head].step+1;                tail++;            }            x=0;            y=n;            z=m;            if(!vis[x][y][z])            {                vis[x][y][z]=1;                q[tail].cup1=x;                q[tail].cup2=y;                q[tail].cup3=z;                q[tail].step=q[head].step+1;                tail++;            }            x=(a-(m-c));                y=b;            z=m;            if(!vis[x][y][z])            {                vis[x][y][z]=1;                q[tail].cup1=x;                q[tail].cup2=y;                q[tail].cup3=z;                q[tail].step=q[head].step+1;                tail++;            }        }        //cup2->cup1|cup2->cup3|\cup2->cup1;        if(b>0)        {            x=a+b;            y=0;            z=c;            if(!vis[x][y][z])            {                vis[x][y][z]=1;                q[tail].cup1=x;                q[tail].cup2=y;                q[tail].cup3=z;                q[tail].step=q[head].step+1;                tail++;            }            if(b+c>=m)            {                x=a;                y=b-(m-c);                z=m;                if(!vis[x][y][z])                {                    vis[x][y][z]=1;                    q[tail].cup1=x;                    q[tail].cup2=y;                    q[tail].cup3=z;                    q[tail].step=q[head].step+1;                    tail++;                }                x=s-m;                y=0;                z=m;                if(!vis[x][y][z])                {                    vis[x][y][z]=1;                    q[tail].cup1=x;                    q[tail].cup2=y;                    q[tail].cup3=z;                    q[tail].step=q[head].step+1;                    tail++;                }            }            else            {                x=a;                y=0;                z=b+c;                if(!vis[x][y][z])                {                    vis[x][y][z]=1;                    q[tail].cup1=x;                    q[tail].cup2=y;                    q[tail].cup3=z;                    q[tail].step=q[head].step+1;                    tail++;                }            }        }        //cup3->cup1|cup3->cup2\\cup3->cup1        if(c>0)        {            x=a+c;            y=b;            z=0;            if(!vis[x][y][z])            {                vis[x][y][z]=1;                q[tail].cup1=x;                q[tail].cup2=y;                q[tail].cup3=z;                q[tail].step=q[head].step+1;                tail++;            }            if(b+c>=n)            {                x=a;                y=n;                z=c-(n-b);                if(!vis[x][y][z])                {                    vis[x][y][z]=1;                    q[tail].cup1=x;                    q[tail].cup2=y;                    q[tail].cup3=z;                    q[tail].step=q[head].step+1;                    tail++;                }                x=s-n;                y=n;                z=0;                if(!vis[x][y][z])                {                    vis[x][y][z]=1;                    q[tail].cup1=x;                    q[tail].cup2=y;                    q[tail].cup3=z;                    q[tail].step=q[head].step+1;                    tail++;                }            }            else            {                x=a;                y=b+c;                z=0;                if(!vis[x][y][z])                {                    vis[x][y][z]=1;                    q[tail].cup1=x;                    q[tail].cup2=y;                    q[tail].cup3=z;                    q[tail].step=q[head].step+1;                    tail++;                }            }        }        head++;    }    printf("NO\n");}int main(){    while(~scanf("%d%d%d",&s,&n,&m))    {        if(s==0&&n==0&&m==0)            break;          if(n<m)        {            int temp=n;            n=m;            m=temp;         }        if(n+m<s||n+m>s||s%2==1)        {            puts("NO");            continue;        }        bfs();    }    return 0;}
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