URAL 1022 Genealogical Tree

URAL_1022

    拓扑排序。

#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;
}