hiho第五十周——欧拉路·二（Fleury算法求欧拉路径）

hiho第五十周——欧拉路·二（Fleury算法求欧拉路径）

注意点

DFS(u):
While (u存在未被删除的边e(u,v))
删除边e(u,v)
DFS(v)
End
PathSize ← PathSize + 1
Path[ PathSize ] ← u

可执行代码

#include <iostream>
#include <fstream>
#include <vector>
using namespace std;

void DFS(int ** graph,vector<int> & path,int start,int size)
{
int i = 0;
while(i<size)
{
if(graph[start][i] != 0)
{
graph[start][i]--;
graph[i][start]--;
DFS(graph,path,i,size);
}
i++;
}
path.push_back(start+1);
return;
}

int main()
{
ifstream cin("input.txt");
int N,M;//岛屿数，骨牌数
cin>>N>>M;
int ** graph = new int*
;
int * degree = new int
;
//图的初始化，度的初始化
for(int i = 0;i < N;i++)
{
graph[i] = new int
;
for(int j = 0;j<N;j++)
graph[i][j] = 0;
degree[i] = 0;
}
int dot1,dot2;
//输入边的信息，同时更新度
for(int i = 0;i<M;i++)
{
cin>>dot1>>dot2;
graph[dot1-1][dot2-1]++;
graph[dot2-1][dot1-1]++;
degree[dot1-1]++;
degree[dot2-1]++;
}

int i = 0;
while(i<N-1 && degree[i]%2 == 0)
i++;

vector<int> path;
DFS(graph,path,i,N);
for(int i=0;i<M;i++)
cout<<path[i]<<" ";
cout<<path[M];

//释放动态申请的空间
for(int i = 0;i < N;i++)
{
delete[] graph[i];
}
delete[] graph;
delete[] degree;
return 0;
}