"POJ 2186" topology sequencing

Test instructions

Given N, which represents the N letters starting with a, gives their m-less relation (A<B).
If the first I relationship can be determined in one order of n letters output:

Sorted sequence determined after I relations: lined letters.

If the first I relationship begins to cause a contradiction, the output is:

Inconsistency found after I relations.

M relationships can not be determined in the order of output:

Sorted sequence cannot be determined.

Code

/*G[I][J] for the adjacency matrix, E[i] for the entry of I in==1 represents a contradiction, the d==1 stands for determining the order so in order */#include <cstdio> #include <cstring> #define N 30int N, M, G[n][n], e[n], C[n], a, B, in, D, So[n];char va, vb;void topo () {memcpy (c, E, sizeof e);//copy E to C, because the following changes to C, the    Can not be used directly with the e int i, top =-1;        for (i = 0; i < n; i++) if (!c[i]) {C[i] = top;//simulates the subscript stack, the point of 0 is passed the subscript stack to top of C = i; } for (i = 0; i < n; i++) {if (top = =-1)//n cycles, if a point of 0 is not found at a time, it returns to the -1 {in = 1;//description        In the ring return;        } int u = top;//with top top = C[u];        So[i] = u;                for (int v = 0; v < n; v++) if (G[u][v] && (--c[v]) = = 0)//The point at which the 0 is removed after you leave the edge { C[V] = top;            Stack top = v;    }} d = 1; for (i = 1; i < n; i++)//Determine if the order is deterministic if (!g[so[i-1]][so[i]]) d = 0;//If there is no partial order relationship between adjacent two, then it is an indeterminate order}int main () {/    /freopen ("In.txt", "R", stdin); while (~SCANF ("%d%d", &n, &m)&& N) {memset (g, 0, sizeof G);        memset (e, 0, sizeof e);        d = in = 0;            for (int i = 1; I <= m; i++) {scanf ("%c<%c", &va, &AMP;VB);            A = va-' a ';            b = vb-' A ';                if (!g[a][b] &&!d &&!in) {g[a][b] = 1;                e[b]++;                Topo ();                if (in) printf ("Inconsistency found after%d relations.\n", i);                    else if (d) {printf ("Sorted sequence determined after%d relations:", I);                    for (int j = 0; J < N; j + +) printf ("%c", So[j] + ' A ');                printf (". \ n");    }}} if (!d &&!in) printf ("Sorted sequence cannot be determined.\n");  }}

　　

"POJ 2186" topology sequencing