hdu 1495 非常可乐（BFS）

题目链接：hdu1495

共有6种操作，x-->y，x-->z，y-->x，y-->z，z-->x，z-->y

#include<stdio.h>
#include<string.h>
#include<algorithm>
#include<queue>
#define MAXN 105
using namespace std;
int v[MAXN][MAXN][MAXN];
int a,b,c,flag;
struct node
{
    int x,y,z;
    int step;
};
bool judge(node k)
{
    if( (k.x == k.y && k.z == 0) || (k.x == k.z && k.y == 0) || (k.z == k.y && k.x == 0) )
    return 1;

    return 0;
}
void bfs()
{
    queue <node> q;
    node s,temp;
    s.x = a;
    s.y = 0;
    s.z = 0;
    s.step = 0;
    v[s.x][s.y][s.z] = 1;//标记该状态已存在过
    q.push(s);
    while(!q.empty())
    {
        temp = q.front();
        q.pop();
        int num;
        if(judge(temp))
        {
            printf("%d
",temp.step);
            flag = 1;
            return ;
        }
        if(temp.x > 0)
        {
            if(temp.y < b)//x-->y
            {
                num = b - temp.y;//表示b中还差多少装满
                s.z = temp.z;
                s.step = temp.step + 1;
                if(temp.x > num)
                {
                    s.x = temp.x - num;
                    s.y = b;
                }
                else
                {
                    s.x = 0;
                    s.y = temp.x + temp.y;
                }
                if(!v[s.x][s.y][s.z])
                {
                    v[s.x][s.y][s.z] = 1;
                    q.push(s);
                }
            }
            if(temp.z < c)//x-->z
            {
                num = c - temp.z;
                s.y = temp.y;
                s.step = temp.step + 1;
                if(temp.x > num)
                {
                    s.x = temp.x - num;
                    s.z = c;
                }
                else
                {
                    s.x = 0;
                    s.z = temp.x + temp.z;
                }
                if(!v[s.x][s.y][s.z])
                {
                    v[s.x][s.y][s.z] = 1;
                    q.push(s);
                }
            }
        }
        if(temp.y > 0)
        {
            if(temp.x < a)//y-->x
            {
                num = a - temp.x;
                s.z = temp.z;
                s.step = temp.step + 1;
                if(temp.y > num)
                {
                    s.y = temp.y - num;
                    s.x = a;
                }
                else
                {
                    s.y = 0;
                    s.x = temp.y + temp.x;
                }
                if(!v[s.x][s.y][s.z])
                {
                    v[s.x][s.y][s.z] = 1;
                    q.push(s);
                }
            }
            if(temp.z < c)//y-->z
            {
                num = c - temp.z;
                s.x = temp.x;
                s.step = temp.step + 1;
                if(temp.y > num)
                {
                    s.y = temp.y - num;
                    s.z = c;
                }
                else
                {
                    s.y = 0;
                    s.z = temp.y + temp.z;
                }
                if(!v[s.x][s.y][s.z])
                {
                    v[s.x][s.y][s.z] = 1;
                    q.push(s);
                }
            }
        }
        if(temp.z > 0)
        {
            if(temp.x < a)//z-->x
            {
                num = a - temp.x;
                s.y = temp.y;
                s.step = temp.step + 1;
                if(temp.z > num)
                {
                    s.z = temp.z - num;
                    s.x = a;
                }
                else
                {
                    s.z = 0;
                    s.x = temp.x + temp.z;
                }
                if(!v[s.x][s.y][s.z])
                {
                    v[s.x][s.y][s.z] = 1;
                    q.push(s);
                }
            }
            if(temp.y < b)//z-->y
            {
                num = b - temp.y;
                s.x = temp.x;
                s.step = temp.step + 1;
                if(temp.z > num)
                {
                    s.z = temp.z - num;
                    s.y = b;
                }
                else
                {
                    s.z = 0;
                    s.y = temp.y + temp.z;
                }
                if(!v[s.x][s.y][s.z])
                {
                    v[s.x][s.y][s.z] = 1;
                    q.push(s);
                }
            }
        }
    }
}
int main()
{
    while(scanf("%d%d%d",&a,&b,&c) && (a + b + c))
    {
        memset(v,0,sizeof(v));
        flag = 0;
        bfs();
        if(!flag) printf("NO
");
    }
    return 0;
}