/* 3414 Pots */#include <iostream>#include <queue>#include <string>#include <string.h>using namespace std;const int MAX = 101;string FILL1 = "FILL(1)\n";string FILL2 = "FILL(2)\n";string POUR1 = "POUR(1,2)\n";string POUR2 = "POUR(2,1)\n";string DROP1 = "DROP(1)\n";string DROP2 = "DROP(2)\n";int visited[MAX][MAX];int a, b, c;struct Node{ int x; int y; int index; string str; Node(int _x, int _y, int _index, string _str): x(_x), y(_y), index(_index), str(_str) {}};void bfs(){ queue<Node> que; Node start = Node(0, 0, 0, ""); que.push( start ); visited[0][0] = 1; while( !que.empty() ) {Node node = que.front();if( node.x == 0 && node.y == 0 ){ string temp = FILL1; Node next1 = Node(a, node.y, node.index + 1, temp); if( visited[next1.x][next1.y] == 0 ) {if( next1.x == c || next1.y == c ) { cout << next1.index << endl << next1.str; return; } visited[next1.x][next1.y] = 1;que.push( next1 ); } string temp2 = FILL2; Node next2 = Node(node.x, b, node.index + 1, node.str + temp2); if( visited[next2.x][next2.y] == 0 ) {if( next2.x == c || next2.y == c ){ cout << next2.index << endl << next2.str; return;}visited[next2.x][next2.y] = 1;que.push( next2 ); }}else if( node.x == 0 && node.y == b ){ Node next = Node(0,0,0,""); if( a >= b ) {next.x = b;next.y = 0; } else {next.x = a;next.y = b - a; } next.index = node.index + 1; string temp = node.str; temp.append( POUR2 ); next.str = temp; if( visited[next.x][next.y] == 0 ) {if( next.x == c || next.y == c ){ cout << next.index << endl << next.str; return;}visited[next.x][next.y] = 1;que.push( next ); }}else if( node.x == a && node.y == 0 ){ Node next = Node(0,0,0,""); if( a >= b ) {next.x = a - b;next.y = b; } else {next.x = 0;next.y = a; } next.index = node.index + 1; string temp = node.str; temp.append( POUR1 ); next.str = temp; if( visited[next.x][next.y] == 0 ) {if( next.x == c || next.y == c ){ cout << next.index << endl << next.str; return;}visited[next.x][next.y] = 1;que.push( next ); }}else if( node.x == 0 && node.y < b && node.y > 0 ){ string temp = node.str; temp.append( FILL1 ); Node next = Node(a, node.y, node.index + 1, temp); if( visited[next.x][next.y] == 0 ) {if( next.x == c || next.y == c ){ cout << next.index << endl << next.str; return;}visited[next.x][next.y] = 1;que.push( next ); } Node next2 = Node(0,0,0,""); if( a > node.y ) {next2.x = node.y;next2.y = 0; } else {next2.x = a;next2.y = node.y - a; } next2.index = node.index + 1; string temp2 = node.str; temp2.append( POUR2 ); next2.str = temp2; if( visited[next2.x][next2.y] == 0 ) {if( next2.x == c || next2.y == c ){ cout << next2.index << endl << next2.str; return;}visited[next2.x][next2.y] = 1;que.push( next2 ); }}else if( node.x < a && node.x > 0 && node. y == 0 ){ string temp = node.str; temp.append( FILL2 ); Node next = Node(node.x, b, node.index + 1, temp); if( visited[next.x][next.y] == 0 ) {if( next.x == c || next.y == c ){ cout << next.index << endl << next.str; return;}visited[next.x][next.y] = 1;que.push( next ); } Node next2 = Node(0,0,0,""); if( b > node.x ) {next2.x = 0;next2.y = node.x; } else {next2.x = node.x - b;next2.y = b; } next2.index = node.index + 1; string temp2 = node.str; temp2.append( POUR1 ); next2.str = temp2; if( visited[next2.x][next2.y] == 0 ) {if( next2.x == c || next2.y == c ){ cout << next2.index << endl << next2.str; return;}visited[next2.x][next2.y] = 1;que.push( next2 ); }}else if( node.x == a && node.y > 0 && node.y < b ){ Node next = Node(0,0,0,""); if( a >= b - node.y ) {next.x = a - b + node.y;next.y = b; } else {next.x = 0;next.y = a + node.y; } next.index = node.index + 1; string temp = node.str; temp.append( POUR1 ); next.str = temp; if( visited[next.x][next.y] == 0 ) {if( next.x == c || next.y == c ){ cout << next.index << endl << next.str; return;}visited[next.x][next.y] = 1;que.push( next ); } string temp2 = node.str; temp2.append( DROP1 ); Node next2 = Node(0, node.y, node.index + 1, temp2); if( visited[next2.x][next2.y] == 0 ) {if( next2.x == c || next2.y == c ){ cout << next2.index << endl << next2.str; return;}visited[next2.x][next2.y] = 1;que.push( next2 ); }}else if( node.y == b && node.x > 0 && node.x < a ){ Node next = Node(0,0,0,""); if( a - node.x >= b ) {next.x = node.x + b;next.y = 0; } else {next.x = a;next.y = b - a + node.x; } next.index = node.index + 1; string temp = node.str; temp.append( POUR2 ); next.str = temp; if( visited[next.x][next.y] == 0 ) {if( next.x == c || next.y == c ){ cout << next.index << endl << next.str; return;}visited[next.x][next.y] = 1;que.push( next ); } string temp2 = node.str; temp2.append( DROP2 ); Node next2 = Node(node.x, 0, node.index + 1, temp2); if( visited[next2.x][next2.y] == 0 ) {if( next2.x == c || next2.y == c ){ cout << next2.index << endl << next2.str; return;}visited[next2.x][next2.y] = 1;que.push( next2 ); }}else if( node.x > 0 && node.y > 0 && node.x < a && node.y < b ){ string temp = node.str; temp.append(DROP1); Node next1 = Node(0, node.y, node.index + 1, temp); if( visited[next1.x][next1.y] == 0 ) {visited[next1.x][next1.y] = 1;que.push( next1 ); } string temp2 = node.str; temp.append( DROP2 ); Node next2 = Node(node.x, 0, node.index + 1, temp2); if( visited[next2.x][next2.y] == 0 ) {visited[next2.x][next2.y] = 1;que.push( next2 ); } Node next3 = Node(0,0,0,""); if( a - node.x >= node.y ) {next3.x = node.x + node.y;next3.y = 0; } else {next3.x = a;next3.y = node.y - a + node.x; } next3.index = node.index + 1; string temp3 = node.str; temp3.append( POUR2 ); next3.str = temp3; if( visited[next3.x][next3.y] == 0 ) {if( next3.x == c || next3.y == c ){ cout << next3.index << endl << next3.str; return;}visited[next3.x][next3.y] = 1;que.push( next3 ); } Node next4 = Node(0,0,0,""); if( node.x >= b - node.y ) {next4.x = node.x - b + node.y;next4.y = b; } else {next4.x = 0;next4.y = node.x + node.y; } next4.index = node.index + 1; string temp4 = node.str; temp4.append( POUR1 ); next4.str = temp4; if( visited[next4.x][next4.y] == 0 ) {if( next4.x == c || next4.y == c ){ cout << next4.index << endl << next4.str; return;}visited[next4.x][next4.y] = 1;que.push( next4 ); }}que.pop(); } cout << "impossible" << endl; return;}int main(){ cin >> a >> b >> c; memset( visited, 0, sizeof(visited) ); bfs(); return 0;}
