Toplogical sort（pku 1094 Sorting It All Out）

Source Code

Problem: 1094 User: SunnaMemory: 180K Time: 0MSLanguage: C++ Result: Accepted

• Source Code

#include <stdio.h>#include <vector>using namespace std;#define NMAX 26#define _determined 1#define _cycle 0#define _n_determined -1int v,e;int map[26][26];int deg[NMAX];vector<int> ansvec;vector<int> odegvec;int Tsort(){//count degint cdel = 0;memset(deg,0,sizeof(deg));odegvec.clear(); ansvec.clear();for (int i=0; i<v; ++i){for (int k=0; k<v; ++k){if (1==map[i][k]) deg[k]++;}}//make stack of 0 degree vertexfor (int i=0; i<v; ++i){if (0==deg[i]){odegvec.push_back(i);}}int cod = odegvec.size(); //count the number of deg[k]==zoreint flag = _determined;if (0==cod) return _cycle;if (cod>1) flag = _n_determined; // ret == _cycle or _n_determined//tsortwhile (!odegvec.empty()){//del the 0 degree tint t = odegvec.back(); odegvec.pop_back(); cdel++;//and add t to the anwser listif (flag != _n_determined) ansvec.push_back(t);//del the edge from tfor (int k=0; k<v; ++k){if (1==map[t][k]){// && 0==del[k]deg[k]--;//a new 0 degree vertexif(0==deg[k])odegvec.push_back(k);}}if (odegvec.size()>1) flag = _n_determined;}//concludeif (v > cdel) return _cycle;if (_n_determined == flag) return _n_determined;int cansvec = ansvec.size();if (v == cansvec) return _determined;}int main(){char low,mid,hi;bool sure;while (scanf("%d %d/n", &v,&e)){if (0==v && 0==e) return 0;memset(map,0,sizeof(map));sure = false;for (int i=0; i<e; ++i){scanf("%c%c%c/n",&low,&mid,&hi);map[low-'A'][hi-'A']=1;// if _cycle or _determined we don't have to apply Tsort()if (sure) continue; // if not sure apply Tsort()int flag = Tsort();if (_n_determined != flag) sure = true;if (_determined == flag){printf("Sorted sequence determined after %d relations: ", i+1);//while (!ansvec.empty()) printf("%c", ansvec.);for (int k=0; k<ansvec.size(); ++k)printf("%c", ansvec[k]+'A');printf("./n");} else if (_cycle == flag){printf("Inconsistency found after %d relations./n", i+1);}}if (!sure)printf("Sorted sequence cannot be determined./n");}return 0;}