9 degree question 1449: Determine the competition rankings, 9 degrees 1449

9 degree question 1449: Determine the competition rankings, 9 degrees 1449

Obviously, the Topology Sorting problem will be found to be easy to understand after drawing a graph. At the beginning, I did not quite understand it myself. After drawing a graph, the idea is very clear.

Reprinted please indicate this article address http://blog.csdn.net/yangnanhai93/article/details/41226221

Question link http://ac.jobdu.com/problem.php? Pid = 1, 1449

#include <iostream>#include <memory.h>#include <queue>using namespace std;int A[501],MapCount[501][501];void TopoSort(int n){    priority_queue<int,vector<int>,greater<int> > qu;    vector<int>result;    for(int i=1;i<=n;i++)        if(A[i]==0)            qu.push(i);    int count=0;    while(!qu.empty())    {        int front=qu.top();        qu.pop();        result.push_back(front);        count++;        for (int i=1;i<=n;i++)        {            if(MapCount[front][i])            {                A[i]--;                if(A[i]==0)                    qu.push(i);            }        }    }    cout<<result[0];    for (int i=1;i<result.size();i++)    {        cout<<" "<<result[i];    }    cout<<endl;}int main(){    //freopen("data.in","r",stdin);    int m,n,x,y;    while(cin>>m>>n&&m)    {        memset(A,0,sizeof(A));        memset(MapCount,0,sizeof(MapCount));        for(int i=0;i<n;i++)        {            cin>>x>>y;            MapCount[x][y]=1;        }        for(int i=1;i<=m;i++)            for(int j=1;j<=m;j++)                if(MapCount[i][j]!=0)                    A[j]++;        TopoSort(m);    }    return 0;}/**************************************************************    Problem: 1449    User: vincent_ynh    Language: C++    Result: Accepted    Time:30 ms    Memory:2500 kb****************************************************************/