USACO Mother's Milk（bfs）

/*
ID: eashion
LANG: C++
TASK: milk3
*/
#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <queue>
#include <algorithm>
#define MAX 22

using namespace std;

struct state{
int a,b,c;
};
int A,B,C;
int save[MAX];
queue<state> Q;
int show[MAX][MAX][MAX];
int main()
{
freopen("milk3.in","r",stdin);
freopen("milk3.out","w",stdout);
while( scanf("%d%d%d",&A,&B,&C) != EOF ){
int pos = 0;
memset(save,0,sizeof(save));
memset(show,0,sizeof(show));
show[0][0][C] = 1;
state tmp;
tmp.a = 0;
tmp.b = 0;
tmp.c = C;
Q.push(tmp);
while( !Q.empty() ){
state cur;
cur = Q.front();
Q.pop();
if( cur.a == 0 ){
save[pos] = cur.c;
pos++;
}
state nstate;
int ta,tb,tc;
if( cur.a != 0 ){
ta = cur.a;
tb = cur.b;
tc = cur.c;
if( ta+tb <= B ){
tb += ta;
ta = 0;
tc = cur.c;
}
else{
ta = ta+tb-B;
tb = B;
tc = cur.c;
}
if( show[ta][tb][tc] != 1 ){
nstate.a = ta;
nstate.b = tb;
nstate.c = tc;
Q.push(nstate);
show[ta][tb][tc] = 1;
}
ta = cur.a;
tb = cur.b;
tc = cur.c;
if( ta+tc <= C ){
tc += ta;
ta = 0;
tb = cur.b;
}
else{
ta = ta+tc-C;
tc = C;
tb = cur.b;
}
if( show[ta][tb][tc] != 1 ){
nstate.a = ta;
nstate.b = tb;
nstate.c = tc;
Q.push(nstate);
show[ta][tb][tc] = 1;
}
}
if( cur.b != 0 ){
ta = cur.a;
tb = cur.b;
tc = cur.c;
if( ta+tb <= A ){
ta += tb;
tb = 0;
tc = cur.c;
}
else{
tb = ta+tb-A;
ta = A;
tc = cur.c;
}
if( show[ta][tb][tc] != 1 ){
nstate.a = ta;
nstate.b = tb;
nstate.c = tc;
Q.push(nstate);
show[ta][tb][tc] = 1;
}
ta = cur.a;
tb = cur.b;
tc = cur.c;
if( tb+tc <= C ){
tc += tb;
tb = 0;
ta = cur.a;
}
else{
tb = tb+tc-C;
tc = C;
ta = cur.a;
}
if( show[ta][tb][tc] != 1 ){
nstate.a = ta;
nstate.b = tb;
nstate.c = tc;
Q.push(nstate);
show[ta][tb][tc] = 1;
}
}
if( cur.c != 0 ){
ta = cur.a;
tb = cur.b;
tc = cur.c;
if( tc+tb <= B ){
tb += tc;
tc = 0;
ta = cur.a;
}
else{
tc = tc+tb-B;
tb = B;
ta = cur.a;
}
if( show[ta][tb][tc] != 1 ){
nstate.a = ta;
nstate.b = tb;
nstate.c = tc;
Q.push(nstate);
show[ta][tb][tc] = 1;
}
ta = cur.a;
tb = cur.b;
tc = cur.c;
if( ta+tc <= A ){
ta += tc;
tc = 0;
tb = cur.b;
}
else{
tc = ta+tc-A;
ta = A;
tb = cur.b;
}
if( show[ta][tb][tc] != 1 ){
nstate.a = ta;
nstate.b = tb;
nstate.c = tc;
Q.push(nstate);
show[ta][tb][tc] = 1;
}
}
}
sort(save,save+pos);
for( int i = 0; i < pos; i++ ){
if( i != pos-1 ){
printf("%d ",save[i]);
}
else{
printf("%d\n",save[i]);
}
}
}
return 0;
}