1.递归

void DFS(ALGraph G, int v)
{visited[v] = 1;printf("%c ", G.vertices[v].data);for (ArcNode* cur = G.vertices[v].firstarc; cur != nullptr; cur = cur->nextarc){if (!visited[cur->adjvex])DFS(G, cur->adjvex);}
}

2.非递归

#include <stack>
#include <iostream>
using namespace std;
void DFS(ALGraph G, int v)
{visited[v] = 1;printf("%c ", G.vertices[v].data);stack<ArcNode*> st;ArcNode* cur = G.vertices[v].firstarc;int index = 0;while (cur || !st.empty()){while (cur){index = cur->adjvex;if (!visited[index]){st.push(cur);visited[index] = 1;printf("%c ", G.vertices[index].data);cur = G.vertices[index].firstarc;}elsecur = cur->nextarc;}if(st.empty())break;cur = st.top();st.pop();cur = cur->nextarc;}
}