可乐倒来倒去的问题，BFS
1 #include <iostream> 2 #include <queue> 3 #include <cstring> 4 using namespace std; 5 struct node{ 6 int s,n,m,t; 7 }now,nxt; 8 int s,n,m; 9 queue<node> q; 10 int flag[105][105][105]; 11 bool check(node a) 12 { 13 return (a.s==a.n&&a.m==0) || (a.s==a.m&&a.n==0) || (a.m==a.n&&a.s==0); 14 } 15 int bfs() 16 { 17 while(!q.empty()) q.pop(); 18 memset(flag,0,sizeof(flag)); 19 now.s=s; 20 now.t=now.n=now.m=0; 21 q.push(now); flag[s][0][0]=1; 22 while(!q.empty()) 23 { 24 now=q.front(); q.pop(); 25 if(check(now)) return now.t; 26 nxt.t=now.t+1; 27 if(now.s<s){//开始强行判断，基本整段复制改一改 28 if(now.m>0){ 29 if(now.m>s-now.s){ 30 nxt.s=s; 31 nxt.m=now.m-(s-now.s); 32 nxt.n=now.n; 33 } else { 34 nxt.s=now.s+now.m; 35 nxt.m=0; 36 nxt.n=now.n; 37 } 38 if(!flag[nxt.s][nxt.m][nxt.n]){ 39 q.push(nxt); flag[nxt.s][nxt.m][nxt.n]=1; 40 } 41 } 42 if(now.n>0){ 43 if(now.n>s-now.s){ 44 nxt.s=s; 45 nxt.n=now.n-(s-now.s); 46 nxt.m=now.m; 47 } else { 48 nxt.s=now.s+now.n; 49 nxt.n=0; 50 nxt.m=now.m; 51 } 52 if(!flag[nxt.s][nxt.m][nxt.n]){ 53 q.push(nxt); flag[nxt.s][nxt.m][nxt.n]=1; 54 } 55 } 56 } 57 if(now.m<m){ 58 if(now.s>0){ 59 if(now.s>m-now.m){ 60 nxt.m=m; 61 nxt.s=now.s-(m-now.m); 62 nxt.n=now.n; 63 } else { 64 nxt.m=now.m+now.s; 65 nxt.s=0; 66 nxt.n=now.n; 67 } 68 if(!flag[nxt.s][nxt.m][nxt.n]){ 69 q.push(nxt); flag[nxt.s][nxt.m][nxt.n]=1; 70 } 71 } 72 if(now.n>0){ 73 if(now.n>m-now.m){ 74 nxt.m=m; 75 nxt.n=now.n-(m-now.m); 76 nxt.s=now.s; 77 } else { 78 nxt.m=now.m+now.n; 79 nxt.n=0; 80 nxt.s=now.s; 81 } 82 if(!flag[nxt.s][nxt.m][nxt.n]){ 83 q.push(nxt); flag[nxt.s][nxt.m][nxt.n]=1; 84 } 85 } 86 } 87 if(now.n<n){ 88 if(now.s>0){ 89 if(now.s>n-now.n){ 90 nxt.n=n; 91 nxt.s=now.s-(n-now.n); 92 nxt.m=now.m; 93 } else { 94 nxt.n=now.n+now.s; 95 nxt.s=0; 96 nxt.m=now.m; 97 } 98 if(!flag[nxt.s][nxt.m][nxt.n]){ 99 q.push(nxt); flag[nxt.s][nxt.m][nxt.n]=1; 100 } 101 } 102 if(now.m>0){ 103 if(now.m>n-now.n){ 104 nxt.n=n; 105 nxt.m=now.m-(n-now.n); 106 nxt.s=now.s; 107 } else { 108 nxt.n=now.n+now.m; 109 nxt.m=0; 110 nxt.s=now.s; 111 } 112 if(!flag[nxt.s][nxt.m][nxt.n]){ 113 q.push(nxt); flag[nxt.s][nxt.m][nxt.n]=1; 114 } 115 } 116 } 117 } 118 return -1; 119 } 120 int main() 121 { 122 while(~scanf("%d%d%d",&s,&n,&m),(n+m+s)) 123 { 124 if(m<n) swap(m,n); 125 int ans=bfs(); 126 if(ans==-1) puts("NO"); 127 else printf("%d ",ans); 128 } 129 }