四叉树 bnuoj
建树+广搜一棵树；最下面有更短代码（很巧妙）。
1 #include<iostream> 2 #include<stdio.h> 3 #include<queue> 4 #include<string.h> 5 #include<algorithm> 6 7 using namespace std; 8 9 int maze[20][20]; 10 struct node 11 { 12 int num; 13 node *next[4]; 14 }; 15 void init_tree(node *root) 16 { 17 int i; 18 for(i=0; i<4; i++) 19 root->next[i] = NULL; 20 } 21 void built(int istart,int iend,int jstart,int jend,node *root) 22 { 23 int dive,i,j; 24 int istart1=istart,iend1=iend,jstart1=jstart,jend1=jend; 25 for(dive=0; dive<4; dive++) 26 { 27 if(dive==0) istart=istart1,iend=istart1+(iend1-istart1+1)/2-1,jstart=jstart1,jend=jstart1+(jend1-jstart1+1)/2-1; 28 else if(dive==1) istart=istart1,iend=istart1+(iend1-istart1+1)/2-1,jstart=jstart1+(jend1-jstart1+1)/2,jend=jend1; 29 else if(dive==2) istart=istart1+(iend1-istart1+1)/2,iend=iend1,jstart=jstart1,jend=jstart1+(jend1-jstart1+1)/2-1; 30 else istart=istart1+(iend1-istart1+1)/2,iend=iend1,jstart=jstart1+(jend1-jstart1+1)/2,jend=jend1; 31 int flag0=0,flag1=0,tree_point; 32 for(i=istart; i<=iend; i++) 33 { 34 for(j=jstart; j<=jend; j++) 35 { 36 if(maze[i][j]==0) flag0=1; 37 if(maze[i][j]==1) flag1=1; 38 } 39 } 40 if(flag0&&flag1) tree_point=2; 41 else if(flag0&&!flag1) tree_point=0; 42 else if(!flag0&&flag1) tree_point=1; 43 node *p; 44 p=new node; 45 init_tree(p); 46 root->next[dive]=p; 47 p->num=tree_point; 48 if(tree_point==1||tree_point==0) continue ; 49 built(istart,iend,jstart,jend,p); 50 } 51 } 52 void print(node *root) 53 { 54 node *ss,*tt; 55 queue<node*>q; 56 q.push(root); 57 while(!q.empty()) 58 { 59 ss=q.front(); 60 int su=ss->num; 61 if(su==2) printf("1"); 62 else if(su==0) printf("00"); 63 else if(su==1) printf("01"); 64 q.pop(); 65 for(int i=0; i<4; i++) 66 { 67 if(ss->next[i] !=NULL) 68 { 69 tt=ss->next[i]; 70 q.push(tt); 71 } 72 } 73 } 74 printf("\n"); 75 } 76 int check_map(int n) 77 { 78 int i,j,sum=0; 79 for(i=1; i<=n; i++) 80 for(j=1; j<=n; j++) 81 sum+=maze[i][j]; 82 if(sum==n*n) return 1; 83 else if(sum==0) return 0; 84 else return -1; 85 } 86 void delete_tree(node *root) 87 { 88 int i; 89 for(i=0; i<4; i++) 90 { 91 if(root->next[i]!=NULL) 92 { 93 delete_tree(root->next[i]); 94 } 95 } 96 delete root; 97 } 98 int main() 99 { 100 int n; 101 while(scanf("%d",&n)!=EOF) 102 { 103 int i,j; 104 memset(maze,0,sizeof(maze)); 105 for(i=1; i<=n; i++) 106 { 107 for(j=1; j<=n; j++) 108 scanf("%d",&maze[i][j]); 109 } 110 int ans=check_map(n); 111 if(ans==0) printf("00\n"); 112 else if(ans==1) printf("01\n"); 113 else 114 { 115 node *tree; 116 tree=new node; 117 init_tree(tree); 118 tree->num=2; 119 built(1,n,1,n,tree); 120 print(tree); 121 delete_tree(tree); 122 } 123 } 124 return 0; 125 }
短代码：
1 #include <cstring> 2 #include <vector> 3 #include<stack> 4 #include<queue> 5 #include<cmath> 6 #include<algorithm> 7 #include<iostream> 8 #include<cstring> 9 //#define N 10005 10 using namespace std; 11 int zu[20][20],n; 12 struct sb 13 { 14 int x,y,x1,y1; 15 bool Get() 16 { 17 int ans=0; 18 for(int i=x;i<=x1;i++) 19 for(int j=y;j<=y1;j++) 20 ans+=zu[i][j]; 21 if(!ans) 22 return true; 23 if(ans==(x1-x+1)*(y1-y+1)) 24 return true; 25 return false; 26 } 27 }; 28 int main() 29 { 30 while(scanf("%d",&n)==1) 31 { 32 for(int i=1;i<=n;i++) 33 for(int j=1;j<=n;j++) 34 scanf("%d",&zu[i][j]); 35 // 36 sb s1,s2; 37 s1.x=1; 38 s1.y=1; 39 s1.x1=n; 40 s1.y1=n; 41 queue<sb>Q; 42 Q.push(s1); 43 while(!Q.empty()) 44 { 45 s1=Q.front(); 46 Q.pop(); 47 if(s1.Get()) 48 { 49 printf("0%d",zu[s1.x1][s1.y1]); 50 continue; 51 } 52 printf("1"); 53 int xx=(s1.x+s1.x1)/2; 54 int yy=(s1.y+s1.y1)/2; 55 s2=s1; 56 s2.y1=yy; 57 s2.x1=xx; 58 Q.push(s2); 59 // 60 s2=s1; 61 s2.x1=xx; 62 s2.y=yy+1; 63 Q.push(s2); 64 // 65 s2=s1; 66 s2.x=xx+1; 67 s2.y1=yy; 68 Q.push(s2); 69 // 70 s2=s1; 71 s2.x=xx+1; 72 s2.y=yy+1; 73 Q.push(s2); 74 } 75 printf("\n"); 76 } 77 }
