URAL 1022 Genealogical Tree

#include<stdio.h>
#include<string.h>
#define MAXD 110
#define MAXM 10010
int N, cnt, e, first[MAXD], next[MAXM], v[MAXM], topo[MAXD], vis[MAXD];
void add(int x, int y)
{
v[e] = y;
next[e] = first[x], first[x] = e ++;
}
void init()
{
int i, j, k;
memset(first, -1, sizeof(first));
e = 0;
for(i = 1; i <= N; i ++)
for(;;)
{
scanf("%d", &k);
if(k == 0)
break;
add(i, k);
}
}
void dfs(int cur)
{
int i;
vis[cur] = 1;
for(i = first[cur]; i != -1; i = next[i])
if(!vis[v[i]])
dfs(v[i]);
topo[-- cnt] = cur;
}
void solve()
{
int i, j, k;
cnt = N;
for(i = 1; i <= N; i ++)
if(!vis[i])
dfs(i);
printf("%d", topo[0]);
for(i = 1; i < N; i ++)
printf(" %d", topo[i]);
printf("\n");
}
int main()
{
while(scanf("%d", &N) == 1)
{
init();
solve();
}
return 0;
}