AOV network and Topology Sorting

/* AOV network and Topology Sorting 1. In a directed acyclic graph, vertices are used to represent activity, and directed edges <u, v> are used to represent activity u first and activity v, this directed graph is called the AOV network. 2. If <u, v>, U is the direct precursor of V, and V is the direct successor of U. If <u, u1, U2, · UN, v> U is the precursor of V, and V is the successor of U. 3. There are transmission and anti-self-defense relationships between the frontend and successor. It can be inferred that the AOV network must be a directed acyclic graph. 4. Implementation of topological sorting: 1) Select a vertex with an inbound degree of 0 from the AOV network and output it; 2) delete the vertex from the AOV network and all edges sent from the vertex; 3) Repeat 1) and 2) until the vertex with an inbound degree of 0 is not found; 4) if all vertices are output, the topology is sorted. Otherwise, the graph has a ring chart. Input Description: The number of vertices N and number of edges m, and the number of m rows is the starting point U and V of each directed edge. The vertex sequence number starts from 1, the last line of the input file is 0 0, indicating the end. Input example: sample output: 6 8 5 1 4 3 2 61 2 network has a cycle! 1 42 63 23 65 15 25 66 81 31 22 53 44 24 65 45 60 0 */# include <stdio. h> # include <string. h> # define maxn 10 struct arcnode {int to; struct arcnode * Next;}; arcnode * list [maxn]; int n, m, Count [maxn]; char output [100]; void topsort () {int I, Top =-1; arcnode * temp; bool bcycle = false; int Pos = 0; for (I = 0; I <n; I ++) if (count [I] = 0) {count [I] = top; Top = I ;}for (I = 0; I <n; I ++) {If (Top =-1) {bcycle = true; break;} el Se {Int J = top; Top = count [Top]; POS + = sprintf (output + POs, "% d", J + 1); temp = list [J]; while (temp! = NULL) {int K = temp-> to; If (-- count [k] = 0) {count [k] = top; Top = K ;} temp = temp-> next ;}}if (bcycle) printf ("network has a cycle! \ N "); else {int Len = strlen (output); Output [len-1] = 0; printf (" % s \ n ", output) ;}} int main () {int I, V, U; // freopen ("input.txt", "r", stdin); While (scanf ("% d", & N, & M )! = EOF) {If (n = 0 & M = 0) break; memset (list, 0, sizeof (list); memset (count, 0, sizeof (count); memset (output, 0, sizeof (output); arcnode * temp; for (I = 0; I <m; I ++) {scanf ("% d", & U, & V); U --; V --; count [v] ++; temp = new arcnode; temp-> to = V; temp-> next = NULL; If (list [u] = NULL) list [u] = temp; else {temp-> next = list [u]; list [u] = temp ;}} topsort (); for (I = 0; I <n; I ++) {temp = list [I]; while (temp! = NULL) {list [I] = temp-> next; Delete temp; temp = list [I] ;}} return 0 ;}