timus 1008. Image encoding

题目大意是一个黑白图像有两种表示方式,给出一种方式,你要输出另一种方式

 

解题报告:

1) 注意是双向转换.所以在输入时必须判断是哪一种情况. 可以应用cin>>first,然后cin.get()!='/n'来判断是不是第一种情况

2) 是一个BFS.

 

#include <iostream> #include <algorithm> #include <vector> #include <queue> #include <string> using namespace std; int a[12][12];//????pixel??? int outLine =1; //??????set,??????queue struct BlackPixel { int x; int y; void Visit() { int flag=0; if (a[x+1][y]==1) cout<<"R"; if (a[x][y+1]==1) cout<<"T"; if (a[x-1][y]==1) cout<<"L"; if (a[x][y-1]==1) cout<<"B"; } }; bool BlackPixel_Compares(BlackPixel a , BlackPixel b) { if (a.x<b.x) return true; else if(a.x>b.x) return false; else if (a.y<b.y) return true; else if(a.y>b.y) return false; else return false; } int main() { vector<BlackPixel> myvector; queue<BlackPixel> myqueue; int n,i,j,k;//black pixel numbers cin>>n; if(cin.get() == '/n') { for (i=0;i<=11;i++) for (j=0;j<=11;j++) a[i][j]=-1; //????white for (i=1;i<=n;i++) { cin>>j>>k; a[j][k]=1; BlackPixel temp; temp.x = j; temp.y = k; myvector.push_back(temp); } BlackPixel root =*min_element(myvector.begin(), myvector.end(), BlackPixel_Compares); cout<<root.x<<" "<<root.y<<endl; myqueue.push(root); while (!myqueue.empty()) { BlackPixel curVal=myqueue.front(); if (a[curVal.x][curVal.y]==2) { myqueue.pop(); continue; } curVal.Visit(); if (outLine++<n) cout<<","<<endl; else cout<<"."<<endl; int x = curVal.x; int y = curVal.y; if (a[x+1][y]==1) { BlackPixel Rtemp; Rtemp.x =x+1; Rtemp.y =y; myqueue.push(Rtemp); a[x+1][y]=0; } if (a[x][y+1]==1) { BlackPixel Ttemp; Ttemp.x =x; Ttemp.y =y+1; myqueue.push(Ttemp); a[x][y+1]=0; } if (a[x-1][y]==1) { BlackPixel Ltemp; Ltemp.x =x-1; Ltemp.y =y; myqueue.push(Ltemp); a[x-1][y]=0; } if (a[x][y-1]==1) { BlackPixel Btemp; Btemp.x =x; Btemp.y =y-1; myqueue.push(Btemp); a[x][y-1]=0; } a[x][y]=2; myqueue.pop(); } } else { BlackPixel leftmin ; leftmin.x = n; cin>>leftmin.y; myqueue.push(leftmin); myvector.push_back(leftmin); while (!myqueue.empty()) { BlackPixel blp = myqueue.front(); string s; cin>>s; if(s.c_str() ==".") break; if (s.size()>1) { for (i=0;i<s.size()-1;i++) { switch(s.c_str()[i]) { case 'R': { BlackPixel temp ; temp.x = blp.x+1; temp.y = blp.y; myqueue.push(temp); myvector.push_back(temp); break; } case 'T': { BlackPixel temp ; temp.x = blp.x; temp.y = blp.y+1; myqueue.push(temp); myvector.push_back(temp); break; } case 'L': { BlackPixel temp ; temp.x = blp.x-1; temp.y = blp.y; myqueue.push(temp); myvector.push_back(temp); break; } case 'B': { BlackPixel temp ; temp.x = blp.x; temp.y = blp.y-1; myqueue.push(temp); myvector.push_back(temp); break; } } } } myqueue.pop(); } sort(myvector.begin(),myvector.end(),BlackPixel_Compares); vector<BlackPixel>::iterator iter; cout<<myvector.size()<<endl; for (iter=myvector.begin();iter!=myvector.end();iter++) { cout<<(*iter).x<<" "<<(*iter).y<<endl; } } return 0; }