Codeforces Round #292 (Div. 1) B. Drazil and Tiles (similar topologies)

Title Link: Http://codeforces.com/problemset/problem/516/B

A n*m square, ' * ' cannot be filled. Give you a lot of 1*2 angle brackets and ask if you can fill the squares with a single fill.

Like Topsort, '. ' Connected to the '. ' in the upper and lower sides. The point from the degree of 1 as a breach.

1 //#pragma COMMENT (linker, "/stack:102400000, 102400000")2#include <algorithm>3#include <iostream>4#include <cstdlib>5#include <cstring>6#include <cstdio>7#include <vector>8#include <queue>9#include <cmath>Ten#include <ctime> One#include <list> A#include <Set> -#include <map> - using namespacestd; thetypedefLong LongLL; -typedef pair <int,int>P; - Const intN = 2e3 +5; - intN, m, tx[] = {-1,0,1,0}, ty[] = {0, -1,0,1}; + CharStr[n][n]; - intdu[n*N]; +Vector <int> g[n*N]; AInlineBOOLJudgeintXinty) { at     if(x >=0&& x < n && y >=0&& y < m && str[x][y] = ='.') -         return true; -     return false; - } -Inlinevoid Get(intXinty) { -      for(inti =0; I <4; ++i) { in         intxx = x + tx[i], yy = y +Ty[i]; -         if(judge (xx, yy)) { toG[x*m + y].push_back (xx*m +yy); +Du[x*m + y]++; -         } the     } * } $InlinevoidChangeintXinty) {Panax Notoginseng     if(M = =1) { -         if(X <y) { thestr[x][0] ='^'; +str[y][0] ='v'; A}Else { thestr[x][0] ='v'; +str[y][0] ='^'; -         } $}Else { $         if(x-y = =-m) { -STR[X/M][X%M] ='^'; -STR[Y/M][Y%M] ='v'; the}Else if(X-y =m) { -STR[X/M][X%M] ='v';WuyiSTR[Y/M][Y%M] ='^'; the}Else if(x-y = =-1) { -STR[X/M][X%M] ='<'; WuSTR[Y/M][Y%M] ='>'; -}Else { AboutSTR[X/M][X%M] ='>'; $STR[Y/M][Y%M] ='<'; -         } -     } - } A  + intMain () the { -     intCNT =0, op =0; $scanf"%d%d", &n, &m); the      for(inti =0; I < n; ++i) { thescanf"%s", Str[i]); the     } the      for(inti =0; I < n; ++i) { -          for(intj =0; J < M; ++j) { in             if(Judge (I, J)) { the                 Get(i, j); the++op; About             } the         } the     } theQueue <int>que; +      for(inti =0; i < n*m; ++i) { -         if(Du[i] = =1) the Que.push (i);Bayi     } the      while(!Que.empty ()) { the         intU =Que.front (); - Que.pop (); -du[u]--; the          for(inti =0; I < g[u].size (); ++i) { the             intv =G[u][i]; thedu[v]--; the             if(Du[v] >0) { -cnt++; the                  for(intj =0; J < G[v].size (); ++j) { thedu[g[v][j]]--; the                     if(Du[g[v][j]] = =1) {94 Que.push (G[v][j]); the                     } the                 } theDU[V] =0;98 Change (U, v); About}Else if(Du[v] = =0) { -cnt++;101 Change (U, v);102             }103         }104     } the     if(CNT *2==op) {106          for(inti =0; I < n; ++i) {107printf"%s\n", Str[i]);108         }109}Else { theprintf"Not unique\n");111     } the     return 0;113}

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Codeforces Round #292 (Div. 1) B. Drazil and Tiles (similar topologies)