题目链接：hdu1495
共有6种操作，x-->y，x-->z，y-->x，y-->z，z-->x，z-->y
#include<stdio.h>#include<string.h>#include<algorithm>#include<queue>#define MAXN 105using namespace std;int v[MAXN][MAXN][MAXN];int a,b,c,flag;struct node{int x,y,z;int step;};bool judge(node k){if( (k.x == k.y && k.z == 0) || (k.x == k.z && k.y == 0) || (k.z == k.y && k.x == 0) )return 1;return 0;}void bfs(){queue <node> q;node s,temp;s.x = a;s.y = 0;s.z = 0;s.step = 0;v[s.x][s.y][s.z] = 1;//标记该状态已存在过q.push(s);while(!q.empty()){temp = q.front();q.pop();int num;if(judge(temp)){printf("%d\n",temp.step);flag = 1;return ;}if(temp.x > 0){if(temp.y < b)//x-->y{num = b - temp.y;//表示b中还差多少装满s.z = temp.z;s.step = temp.step + 1;if(temp.x > num){s.x = temp.x - num;s.y = b;}else{s.x = 0;s.y = temp.x + temp.y;}if(!v[s.x][s.y][s.z]){v[s.x][s.y][s.z] = 1;q.push(s);}}if(temp.z < c)//x-->z{num = c - temp.z;s.y = temp.y;s.step = temp.step + 1;if(temp.x > num){s.x = temp.x - num;s.z = c;}else{s.x = 0;s.z = temp.x + temp.z;}if(!v[s.x][s.y][s.z]){v[s.x][s.y][s.z] = 1;q.push(s);}}}if(temp.y > 0){if(temp.x < a)//y-->x{num = a - temp.x;s.z = temp.z;s.step = temp.step + 1;if(temp.y > num){s.y = temp.y - num;s.x = a;}else{s.y = 0;s.x = temp.y + temp.x;}if(!v[s.x][s.y][s.z]){v[s.x][s.y][s.z] = 1;q.push(s);}}if(temp.z < c)//y-->z{num = c - temp.z;s.x = temp.x;s.step = temp.step + 1;if(temp.y > num){s.y = temp.y - num;s.z = c;}else{s.y = 0;s.z = temp.y + temp.z;}if(!v[s.x][s.y][s.z]){v[s.x][s.y][s.z] = 1;q.push(s);}}}if(temp.z > 0){if(temp.x < a)//z-->x{num = a - temp.x;s.y = temp.y;s.step = temp.step + 1;if(temp.z > num){s.z = temp.z - num;s.x = a;}else{s.z = 0;s.x = temp.x + temp.z;}if(!v[s.x][s.y][s.z]){v[s.x][s.y][s.z] = 1;q.push(s);}}if(temp.y < b)//z-->y{num = b - temp.y;s.x = temp.x;s.step = temp.step + 1;if(temp.z > num){s.z = temp.z - num;s.y = b;}else{s.z = 0;s.y = temp.y + temp.z;}if(!v[s.x][s.y][s.z]){v[s.x][s.y][s.z] = 1;q.push(s);}}}}}int main(){while(scanf("%d%d%d",&a,&b,&c) && (a + b + c)){memset(v,0,sizeof(v));flag = 0;bfs();if(!flag) printf("NO\n");}return 0;}
