Codeforces Round #292 (Div. 1) B. Drazil and Tiles (topological sort)

Title Address: Codeforces 292 B
Use the queue to maintain a point with a degree of 1, that is, a point that can be uniquely determined, and then each time you find V1,v2, and v2 to update the points connected to it, if the updated point is 1, join the queue. If there is a final "." , stating that no solution or solution is unique.
The code is as follows:

#include <iostream>#include <string.h>#include <math.h>#include <queue>#include <algorithm>#include <stdlib.h>#include <map>#include <set>#include <stdio.h>using namespace STD;#pragma COMMENT (linker, "/stack:102400000,102400000")#define LL __int64#define PI ACOs ( -1.0)Const intMod=1e9+7;Const intinf=0x3f3f3f3f;Const Doubleeqs=1e-9;intjx[]={0,0,1,-1};intjy[]={1,-1,0,0};intd[5002][5002], N, m;Charmp[5002][5002];structnode{intx, y;}; queue<node>QBOOLTopo () {intI, J, K, X, Y, A, B, H; Node F1, F2; while(!q.empty ())                {F1=q.front (); Q.pop ();if(!d[f1.x][f1.y])Continue; d[f1.x][f1.y]=0; for(k=0;k<4; k++) {x=f1.x+jx[k]; Y=F1.Y+JY[K];if(x>=0&&x<n&&y>=0&&y<m&&mp[x][y]=='. ') {d[x][y]--;if(k==0) {mp[f1.x][f1.y]=' < '; mp[x][y]=' > '; }Else if(k==1) {mp[f1.x][f1.y]=' > '; mp[x][y]=' < '; }Else if(k==2) {mp[f1.x][f1.y]=' ^ '; mp[x][y]=' V '; }Else{mp[f1.x][f1.y]=' V '; mp[x][y]=' ^ '; } for(h=0;h<4; h++) {a=x+jx[h]; B=Y+JY[H];if(a>=0&&a<n&&b>=0&&b<m&&mp[a][b]=='. ') {d[a][b]--;if(d[a][b]==1) {f2.x=a;f2.y=b;                                                Q.push (F2);        }                                        }                                }                        }                } } for(i=0; i<n;i++) { for(j=0; j<m;j++) {if(mp[i][j]=='. ')return 0; }        }return 1;}intMain () {intI, J, X, Y, cnt, k, ans; while(scanf("%d%d", &n,&m)!=eof) { for(i=0; i<n;i++) {scanf('%s ', Mp[i]); } node F; for(i=0; i<n;i++) { for(j=0; j<m;j++) {if(mp[i][j]!='. ')Continue; Cnt=0; for(k=0;k<4; k++) {x=i+jx[k]; Y=J+JY[K];if(x>=0&&x<n&&y>=0&&y<m&&mp[x][y]=='. ') cnt++; } d[i][j]=cnt;if(cnt==1) {f.x=i;f.y=j;                                Q.push (f); }                        }                }if(Topo ()) { for(i=0; i<n;i++) {printf("%s\n", Mp[i]); }                }Else puts("Not unique"); }return 0;}

Codeforces Round #292 (Div. 1) B. Drazil and Tiles (topological sort)