HDU 1495 & [kuangbin带你飞]专题一 简单搜索 M

M - 非常可乐

大家一定觉的运动以后喝可乐是一件很惬意的事情，但是seeyou却不这么认为。因为每次当seeyou买了可乐以后，阿牛就要求和seeyou一起分享这一瓶可乐，而且一定要喝的和seeyou一样多。但seeyou的手中只有两个杯子，它们的容量分别是N 毫升和M 毫升 可乐的体积为S （S<101）毫升　(正好装满一瓶) ，它们三个之间可以相互倒可乐 (都是没有刻度的，且 S==N+M，101＞S＞0，N＞0，M＞0) 。聪明的ACMER你们说他们能平分吗？如果能请输出倒可乐的最少的次数，如果不能输出”NO”。
Input
三个整数 : S 可乐的体积 , N 和 M是两个杯子的容量，以”0 0 0”结束。
Output
如果能平分的话请输出最少要倒的次数，否则输出”NO”。
Sample Input
7 4 3
4 1 3
0 0 0
Sample Output
NO
3

#include<bits/stdc++.h>using namespace std;using LL=int64_t;const int INF=0x3f3f3f3f;int sum,s,n,m;struct Node {    int s,n,m;    int step;    friend operator < (Node a, Node b) {        return a.step>b.step;    }}ans;bool book[105][105][105];void bfs() {    memset(book,false,sizeof(book)) ;    priority_queue<Node>Q;    Node now,next;    now.s=s,now.m=now.n=now.step=0;    book[now.s][now.m][now.n]=true;    Q.push(now);    while(! Q.empty()) {        now=Q.top();        Q.pop();        if((now.s==s/2&&now.m==s/2)||(now.m==s/2&&now.n==s/2)||(now.n==s/2&&now.s==s/2)) {            sum=now.step;            return ;        }        next.step=now.step+1;        if(now.s>0) {            if(now.m<m) {                if(now.s>m-now.m)  {                    next.s=now.s-(m-now.m);                    next.m=m;                    next.n=now.n;                    if(book[next.s][next.m][next.n]==false) {                        Q.push(next);                        book[next.s][next.m][next.n]=true;                    }                }                else if(now.s<=m-now.m) {                    next.s=0;                    next.m=now.s+now.m;                    next.n=now.n;                    if(book[next.s][next.m][next.n]==false) {                        Q.push(next);                        book[next.s][next.m][next.n]=true;                    }                }            }            if(now.n<n) {                if(now.s>n-now.n)  {                    next.s=now.s-n+now.n;                    next.m=now.m;                    next.n=n;                    if(book[next.s][next.m][next.n]==false) {                        Q.push(next);                        book[next.s][next.m][next.n]=true;                    }                }                else if(now.s<=n-now.n) {                    next.s=0;                    next.m=now.m;                    next.n=now.n+now.s;                    if(book[next.s][next.m][next.n]==false) {                        Q.push(next);                        book[next.s][next.m][next.n]=true;                    }                }            }        }        if(now.m>0) {            if(now.s<s) {                if(now.m>s-now.s) {                    next.s=s;                    next.m=now.m-s+now.s;                    next.n=now.n;                    if(book[next.s][next.m][next.n]==false) {                        Q.push(next);                        book[next.s][next.m][next.n]=true;                    }                }                if(now.m<=s-now.s) {                    next.s=now.s+now.m;                    next.m=0;                    next.n=now.n;                    if(book[next.s][next.m][next.n]==false) {                        Q.push(next);                        book[next.s][next.m][next.n]=true;                    }                }            }            if(now.n<n) {                if(now.m<=n-now.n) {                    next.s=now.s;                    next.m=0;                    next.n=now.n+now.m;                    if(book[next.s][next.m][next.n]==false) {                        Q.push(next);                        book[next.s][next.m][next.n]=true;                    }                }                else if(now.m>n-now.n) {                    next.s=now.s;                    next.m=now.m-n+now.n;                    next.n=n;                    if(book[next.s][next.m][next.n]==false) {                        Q.push(next);                        book[next.s][next.m][next.n]=true;                    }                }            }        }        if(now.n>0) {            if(now.s<s) {                if(now.n>s-now.s) {                    next.s=s;                    next.m=now.m;                    next.n=now.n-s+now.s;                    if(book[next.s][next.m][next.n]==false) {                        Q.push(next);                        book[next.s][next.m][next.n]=true;                    }                }                if(now.n<=s-now.s) {                    next.s=now.s+now.n;                    next.m=now.m;                    next.n=0;                    if(book[next.s][next.m][next.n]==false) {                        Q.push(next);                        book[next.s][next.m][next.n]=true;                    }                }            }            if(now.m<m) {                if(now.n<=m-now.m) {                    next.s=now.s;                    next.m=now.m+now.n;                    next.n=0;                    if(book[next.s][next.m][next.n]==false) {                        Q.push(next);                        book[next.s][next.m][next.n]=true;                    }                }                else if(now.n>m-now.m) {                    next.s=now.s;                    next.m=m;                    next.n=now.n-m+now.m;                    if(book[next.s][next.m][next.n]==false) {                        Q.push(next);                        book[next.s][next.m][next.n]=true;                    }                }            }        }    }    return ;}int main(){    ios::sync_with_stdio(0);    cin.tie(0);    while(cin>>s>>n>>m&&s) {        if(s%2==1) {cout<<"NO"<<endl;continue;}        sum=0;        bfs();        if(sum==0) cout<<"NO"<<endl;        else cout<<sum<<endl;    }    return 0;}