POJ 3414 Pots (bfs+ path record)

Pots

Time Limit: 1000MS		Memory Limit: 65536K
Total Submissions: 11703		Accepted: 4955		Special Judge

Description

You are given the pots of the volume of A and B liters respectively. The following operations can be performed:

1. Fill (i) Fill the pot i (1≤ i ≤ 2) from the tap;
2. DROP (i) empty the pot I to the drain;
3. Pour (i,j) pour from pot i to pot J; After this operation either the pot J was full (and there may be some water left in the pot I), or the PO T I was empty (and all its contents has been moved to the pot J).

Write a program to find the shortest possible sequence of these operations that'll yield exactly C liters of Water in one of the pots.

Input

On the first and only line is the numbers A, B, and C. These is all integers in the range from 1 to + C≤max (A,B).

Output

The first line of the output must contain the length of the sequence of operations K. The following K lines must each describe one operation. If There is several sequences of minimal length, output any one of them. If the desired result can ' t is achieved, the first and only line of the file must contain the word 'impossible'.

Sample Input

3 5 4

Sample Output

6FILL (2) pour (2,1) DROP (1) pour (2,1) FILL (2) pour (2,1)

It's cool, once again AC

/************************************************************************* > File name:code/2015summer/ Searching/h.cpp > Author:111qqz > Email: [email protected] > Created time:2015 July 27 Monday 09:11 28 seconds * ***********************************************************************/#include<iostream>#include<iomanip>#include<cstdio>#include<algorithm>#include<cmath>#include<cstring>#include<string>#include<map>#include<Set>#include<queue>#include<vector>#include<stack>#defineY0 ABC111QQZ#defineY1 HUST111QQZ#defineYn hez111qqz#defineJ1 CUTE111QQZ#defineTM CRAZY111QQZ#defineLR DYING111QQZusing namespacestd;#defineREP (i, n) for (int i=0;i<int (n); ++i)typedefLong Longll;typedef unsignedLong LongULL;Const intn=1e2+5;inta,b,c;intD[n][n];BOOLFlag;structnode{intD,opt,par,prea,preb;} Q[n][n];voidPrintintXinty) { //cout<< "x:" <<x<< "y:" <<y<<endl;    if(q[x][y].prea!=-1&&q[x][y].preb!=-1)    {//cout<< "Who is 111qqz" <<endl;print (Q[X][Y].PREA,Q[X][Y].PREB); if(q[x][y].opt==1) {printf ("FILL (%d) \ n", Q[x][y].par); }      if(q[x][y].opt==2) {printf ("DROP (%d) \ n", Q[x][y].par); }      if(q[x][y].opt==3) {printf ("pour (%d,%d) \ n", Q[x][y].par,3-Q[x][y].par); }    }}voidBFs () {memset (q,-1,sizeof(q)); Queue<int>A; Queue<int>b; A.push (0); B.push (0); q[0][0].d=0;  while(!a.empty () &&!B.empty ()) {      intAV =A.front (); A.pop (); intBV =B.front (); B.pop ();//cout<< "av:" <<av<< "BV:" <<bv<<endl;      if(av==c| | bv==C) {flag=true; //cout<< "yeah~~~~~~~~~~~~~~~" <<endl;cout<<q[av][bv].d<<Endl;//cout<< "Prea:" <<q[av][bv].prea<< "Preb:" <<q[av][bv].preb<<endl;print (AV,BV); return; }      if(av<a&&q[a][bv].d==-1) {Q[A][BV].D=q[av][bv].d+1; Q[a][bv].opt=1; Q[a][bv].par=1; Q[a][bv].prea=av; Q[a][bv].preb=BV;        A.push (A);      B.push (BV); }      if(av>0&&q[0][bv].d==-1) {q[0][bv].d=q[av][bv].d+1; q[0][bv].opt=2; q[0][bv].par=1; q[0][bv].prea=av; q[0][bv].preb=BV; A.push (0);      B.push (BV); }      if(bv<b&&q[av][b].d==-1) {Q[AV][B].D=q[av][bv].d+1; Q[av][b].opt=1; Q[av][b].par=2; Q[av][b].prea=av; Q[av][b].preb=BV;        A.push (AV);              B.push (B); }      if(bv>0&&q[av][0].d==-1) {q[av][0].d=q[av][bv].d+1; q[av][0].opt=2; q[av][0].par=2; q[av][0].prea=av; q[av][0].preb=v;        A.push (AV); B.push (0); }      if(av+bv<=b&&q[0][av+bv].d==-1) {q[0][av+bv].d=q[av][bv].d+1; q[0][av+bv].opt=3; q[0][av+bv].par=1; q[0][av+bv].prea=av; q[0][av+bv].preb=BV; A.push (0); B.push (AV+BV); }      if(av+bv>b&&q[av-(B-BV)][b].d==-1)//two cases of pouring 1 into 2      {              intTMP = av-(b-BV); Q[TMP][B].D=q[av][bv].d+1; Q[tmp][b].opt=3; Q[tmp][b].par=1; Q[tmp][b].prea=av; Q[tmp][b].preb=v;        A.push (TMP);      B.push (B); }      if(bv+av<=a&&q[av+bv][0].d==-1) {Q[av+bv][0].d=q[av][bv].d+1; Q[av+bv][0].opt=3; Q[av+bv][0].par=2; Q[av+bv][0].prea=av; Q[av+bv][0].preb=v; A.push (AV+BV); B.push (0); }      if(bv+av>a&&q[a][bv-(A-AV)].d==-1)      {        intTMP = bv-(A-av); Q[A][TMP].D=q[av][bv].d+1; Q[a][tmp].opt=3; Q[a][tmp].par=2; Q[a][tmp].prea=av; Q[a][tmp].preb=BV;        A.push (A);      B.push (TMP); }    }}intMain () {flag=false; CIN>>A>>B>>C;    BFS (); if(!flag) {cout<<"Impossible"<<Endl; }            return 0;}

POJ 3414 Pots (bfs+ path record)