poj 2367(拓扑排序TopSort)

来源：互联网发布：集合和数组的优缺点编辑：程序博客网时间：2024/05/16 09:47

题意简单，说到底就是求符合的拓扑排序。

代码如下：

#include <iostream>#include <cstdio>#include <cstring>#define maxn 100using namespace std;struct edge { int v, next; };int g[maxn], n, list[maxn];edge e[maxn*maxn];bool topsortdfs( int v, edge e[], int g[], int u[], int &m ){    u[v] = -2;    for ( int i = g[v]; i != -1; i = e[i].next )        if ( u[e[i].v]==-2 ) return false;        else if ( u[e[i].v]==-1 && !topsortdfs(e[i].v,e,g,u,m) ) return false;    u[v] = --m;    return true;}void topsort( edge e[], int g[], int n, int list[] ){    static int u[maxn];    int m = n, i;    memset(u,255,sizeof(u));    for ( i = 0; i < n; i++ )        if ( u[i]==-1 && !topsortdfs(i,e,g,u,m) ) return;    for ( i = 0; i < n; i++ )        list[u[i]] = i;    printf( "%d", list[0]+1 );    for ( i = 1; i < n; i++ )        printf( " %d", list[i]+1 );    printf( "\n" );}int main(){    int i, j, k;    cin >> n ;    memset(g,255,sizeof(g));    for ( i = j = 0; i < n; i++ )    while ( scanf("%d", &k) )    {        if ( k == 0 ) break;        k--;        e[j].v = k; e[j].next = g[i];  g[i] = j++;    }    topsort( e,g,n,list);}