Graph algorithm (a)--basic graph algorithm (BFS,DFS and its application) (2)

2) DFS

The depth-first search always searches for the starting edge of the recently discovered node v until all the departure edges of that node are discovered

Once all the starting edges of node v are found, the search is traced back to the V's precursor node.

Implementation Details: Timestamp

Each node has a discovery time and a completion time.

The precursor of a DFS rear image forms a depth-first forest

1#include <iostream>2 using namespacestd;3 #defineNIL-14 intg[ +][ +];5 intN;6 structNode7 {8     intcolor;9     intD;Ten     intF; One     intPi; A}t[ +]; - intTime ; -  the voidDFS (); - voidDfs_visit (intu); -  - voidDFS () + { -      for(intI=0; i<n;i++) +     { AT[i].color =0; atT[i].pi =NIL; -     } -Time=1; -      for(intI=0; i<n;i++) -     { -         if(T[i].color = =0) in dfs_visit (i); -     } to } + voidDfs_visit (intu) - { theT[U].D = time++; *T[u].color =1;/*****/ $      for(intv=0; v<n;v++)Panax Notoginseng     { -         if((g[u][v] = =1) && (T[v].color = =0)) the         { +T[v].pi =u; A Dfs_visit (v); the         } +     } -T[U].F = time++; $ } $ /* - int main () - { the While (cin>>n) -     {Wuyi for (int i=0;i<n;i++) the         { - for (int j=0;j<n;j++) Wu             { - cin>>g[i][j]; About             } $         } - DFS (); - for (int i=0;i<n;i++) - cout<<i<< "<<t[i].d<<" "<<t[i].f<<" "<<endl; A     } + return 0; the } - */

Graph algorithm (a)--basic graph algorithm (BFS,DFS and its application) (2)