贴一发自己写的手写队列…..

#include <stdio.h>
#include <iostream>
#include <string.h>
#include <math.h>
#include <stdlib.h>
#include <queue>
#include <set>
#include <stack>
#include <algorithm>
using namespace std;
#define PI acos(-1.0)
#define INF 0x7fffffff
#define N 1010
struct asd
{int a,b;int flag;int step;
} q[N];
int pre[N];
int vis[N][N];
int head,rail;
void pri()
{printf("impossible\n");
}
void print(int x)
{int t;t=pre[x];if(t==0){if(q[x].flag==0){printf("FILL(1)\n");}else if(q[x].flag==1){printf("FILL(2)\n");}else if(q[x].flag==2){printf("DROP(1)\n");}else if(q[x].flag==3){printf("DROP(2)\n");}else if(q[x].flag==4){printf("POUR(2,1)\n");}else if(q[x].flag==5){printf("POUR(1,2)\n");}return;}else{print(t);}if(q[x].flag==0){printf("FILL(1)\n");}else if(q[x].flag==1){printf("FILL(2)\n");}else if(q[x].flag==2){printf("DROP(1)\n");}else if(q[x].flag==3){printf("DROP(2)\n");}else if(q[x].flag==4){printf("POUR(2,1)\n");}else if(q[x].flag==5){printf("POUR(1,2)\n");}
}void bfs(int n,int m,int c)
{memset(vis,0,sizeof(vis));head=0;rail=1;q[0].a=0;q[0].b=0;q[0].flag=-1;q[0].step=0;vis[0][0]=1;pre[0]=-1;while(head<rail){//printf("%d\n",head);int x=q[head].a;int y=q[head].b;if(x==c||y==c){printf("%d\n",q[head].step);print(head);return;}for(int i=0; i<6; i++){if(i==0){q[rail].a=n;q[rail].b=q[head].b;q[rail].flag=0;}else if(i==1){q[rail].a=q[head].a;q[rail].b=m;q[rail].flag=1;}else if(i==2){q[rail].a=0;q[rail].b=q[head].b;q[rail].flag=2;}else if(i==3){q[rail].a=q[head].a;q[rail].b=0;q[rail].flag=3;}else if(i==4){// printf("aaa\n");if((q[head].b+q[head].a)>=n){q[rail].a=n;q[rail].b=q[head].b-(n-q[head].a);q[rail].flag=4;}else if((q[head].b+q[head].a)<n){q[rail].a=q[head].a+q[head].b;q[rail].b=0;q[rail].flag=4;}// printf("%d %d\n",q[rail].a,q[rail].b);}else if(i==5){if((q[head].a+q[head].b)>=m){q[rail].a=q[head].a-(m-q[head].b);q[rail].b=m;q[rail].flag=5;}else if((q[head].a+q[head].b)<m){q[rail].a=0;q[rail].b=q[head].b+q[head].a;q[rail].flag=5;}}//printf("%d %d\n",q[rail].a,q[rail].b);if(vis[q[rail].a][q[rail].b])continue;vis[q[rail].a][q[rail].b]=1;q[rail].step=q[head].step+1;pre[rail]=head;rail++;if(q[rail].b==c||q[rail].a==c){//printf("aaa\n");printf("%d\n",q[head].step+1);print(rail);return;}}head++;}pri();return;
}
int main()
{int n,m,c;while(~scanf("%d%d%d",&n,&m,&c)){// printf("%d %d %d\n",n,m,c);bfs(n,m,c);}return 0;
}