"POJ" 3678 katu Puzzle

Simple 2-sat.

1 /*3678*/2#include <iostream>3#include <algorithm>4#include <cstdio>5#include <cstring>6#include <cstdlib>7 using namespacestd;8 9 #defineMAXN 1005Ten #defineMaxe 1000005 One  Atypedefstruct { -     intV, next; - } edge_t; the  - intpre[maxn*2], low[maxn*2]; - intbn[maxn*2]; - intDfs_clock, block; + ints[maxn*2], top; - inthead[maxn*2], L; + edge_t E[maxe]; A intN, M, N2; at intA[maxe], B[maxe], c[maxe]; - CharOp[maxe]; -  - voidAddedge (intUintv) { -E[L].V =v; -E[l].next =Head[u]; inHead[u] = l++; - } to  + voidinit () { -Dfs_clock = block = top = L =0; thememset (PRE,0,sizeof(int)*n2); *Memset (BN,0,sizeof(int)*n2); $Memset (Head,-1,sizeof(int)*n2);Panax Notoginseng } -  the voidDfsintu) { +     intI, J, K, V; A      thes[top++] =u; +Pre[u] = Low[u] = + +Dfs_clock; -      for(I=head[u]; i!=-1; I=E[i].next) { $v =e[i].v; $         if(!Pre[v]) { - Dfs (v); -Low[u] =min (Low[u], low[v]); the}Else if(!Bn[v]) { -Low[u] =min (Low[u], pre[v]);Wuyi         } the     } -     if(Low[u] = =Pre[u]) { Wu++Block; -          Do { AboutBn[s[--top]] =Block; $} while(s[top]!=u); -     } - } -  A  +  the intMain () { -     intI, J, K; $     intII, JJ; the     Charcmd[8]; the     BOOLFlag; the      the #ifndef Online_judge -Freopen ("data.in","R", stdin); inFreopen ("Data.out","W", stdout); the     #endif the      About      while(SCANF ("%d%d", &n,&m)! =EOF) { theN2 = n+N; the          for(i=0; i<m; ++i) { thescanf"%d %d%d%s", &a[i], &b[i], &c[i], cmd); +Op[i] = cmd[0]; -         } theFlag =true;Bayi          for(k=0; flag&&k< +; ++k) { the init (); the              for(i=0; i<m; ++i) { -II = a[i]+A[i]; -JJ = b[i]+B[i]; the                 if(Op[i] = ='A') { the                     // and the                     if(C[i] & (1<<k)) { theAddedge (II, ii+1); -Addedge (ii+1, jj+1); theAddedge (JJ, jj+1); theAddedge (jj+1, ii+1); the}Else {94Addedge (ii+1, JJ); theAddedge (jj+1, ii); the                     } the}Else if(Op[i] = ='O') {98                     //or About                     if(C[i] & (1<<k)) { -Addedge (II, jj+1);101Addedge (JJ, ii+1);102}Else {103 Addedge (ii, JJ);104 Addedge (JJ, ii); theAddedge (ii+1, ii);106Addedge (jj+1, JJ);107                     }108}Else if(Op[i] = ='X') {109                     //XOR the                     if(C[i] & (1<<k)) {111Addedge (II, jj+1); theAddedge (ii+1, JJ);113Addedge (JJ, ii+1); theAddedge (jj+1, ii); the}Else { the Addedge (ii, JJ);117Addedge (ii+1, jj+1);118 Addedge (JJ, ii);119Addedge (jj+1, ii+1); -                     }121                 }122             }123              for(i=0; i<n2; ++i)124                 if(!Pre[i]) the DFS (i);126              for(i=0; flag&&i<n2; i+=2)127                 if(Bn[i] = = bn[i+1]) -Flag =false;129         } the         if(flag)131Puts"YES"); the         Else133Puts"NO");134     }135     136     return 0;137}

"POJ" 3678 katu Puzzle