图搜索的API
起点（source）简单记为s。
如图marked()给出图中v和s有没有相连关系。
深度优先搜索
#pragma once
#include"Graph.h"
class depthFirstSearch
{
public:
depthFirstSearch(Graph& G, int s);
int count() {
return m_count; }
bool marked(int v) {
return m_marked->at(v); }
private:
vector<bool>* m_marked;//标记是否相连
int m_count;//与source起点连通的顶点数，包括自己
void dfs(Graph& G, int now);
};
depthFirstSearch::depthFirstSearch(Graph& G, int s)
{
m_marked = new vector<bool>(G.V(), false);
m_count = 0;
dfs(G, s);
}
inline
void depthFirstSearch::dfs(Graph& G, int now)
{
m_marked->at(now) = true;
m_count++;
for (const auto &next : G.adj(now)) {
if (!(*m_marked)[next]) {
dfs(G, next);
}
}
}
广搜
#pragma once
#include<queue>
#include"Graph.h"
class breadthFirstSearch {
public:
breadthFirstSearch(Graph& G, int s);
int count() {
return m_count; }
bool marked(int v) {
return (*m_marked)[v]; }
private:
vector<bool>* m_marked=nullptr;
int m_count = 0;//相连通的节点，不包括自己
void bfs(Graph& G, int now);
};
breadthFirstSearch::breadthFirstSearch(Graph& G, int s)
{
m_marked = new vector<bool>(G.V(), false);
m_count = 0;
bfs(G, s);
}
inline void breadthFirstSearch::bfs(Graph& G, int now)
{
queue<int> Q;
(*m_marked)[now] = true;
Q.push(now);
while (!Q.empty()) {
int v = Q.front();Q.pop();//从队列中删除下一顶点
for (auto& w : G.adj(v)) {
if (!(*m_marked)[w]) {
//邻接点未被标记
m_marked->at(w) = true;//标记它，并入队
++m_count;//这里是可变的，其他部分算固定框架
Q.push(w);
}
}
}
}
关于测试
图的头文件和数据文件在这里：从文件读取构建图https://blog.csdn.net/qq_34890856/article/details/112938237
#include"depthFirstSearch.h"
//#include"breadthFirstSearch.h"
#define out(x) cout<<x<<" "
#define hh printf_s("\n")
void testDFS() {
Graph G("data.txt");
depthFirstSearch dfsG(G, 9);
bool isconnected = dfsG.marked(0);
int n = dfsG.count();
out("9 0 connected ? "), out(isconnected), hh;
out("how many connect to 9 ? "), out(n), hh;
//out(G.toString());
}
int main() {
testDFS();
system("pause");
return 0;
}