codes/LP2/uninformed_cpp_BFS.cpp at main · GetSomeSleepBro/codes · GitHub

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// Uninformed Search: BFS
#include <algorithm>
#include <iostream>
#include <queue>
#include <vector>

static std::vector<int> bfs_path(const std::vector<std::vector<int>>& graph, int start, int goal) {
    int n = (int)graph.size();
    std::vector<int> prev(n, -1);
    std::vector<bool> visited(n, false);
    std::queue<int> q;

    visited[start] = true;
    q.push(start);

    while (!q.empty()) {
        int u = q.front();
        q.pop();
        if (u == goal) break;
        for (int v : graph[u]) {
            if (!visited[v]) {
                visited[v] = true;
                prev[v] = u;
                q.push(v);
            }
        }
    }

    if (!visited[goal]) return {};
    std::vector<int> path;
    for (int at = goal; at != -1; at = prev[at]) path.push_back(at);
    std::reverse(path.begin(), path.end());
    return path;
}

int main() {
    std::vector<std::vector<int>> graph = {
        {1, 2},    // 0
        {3, 4},    // 1
        {5},       // 2
        {6},       // 3
        {6},       // 4
        {6},       // 5
        {}         // 6
    };

    int start = 0, goal = 6;
    auto path = bfs_path(graph, start, goal);

    if (path.empty()) {
        std::cout << "No path\n";
        return 0;
    }

    std::cout << "BFS Path: ";
    for (size_t i = 0; i < path.size(); i++) {
        if (i) std::cout << " -> ";
        std::cout << path[i];
    }
    std::cout << "\n";
    return 0;
}


// #include <bits/stdc++.h>
// using namespace std;

// void bfs(int start, vector<vector<int>>& graph) {
//     vector<bool> visited(graph.size(), false);
//     queue<int> q;

//     visited[start] = true;
//     q.push(start);

//     while (!q.empty()) {
//         int node = q.front();
//         q.pop();

//         cout << node << " ";

//         for (int neighbor : graph[node]) {
//             if (!visited[neighbor]) {
//                 visited[neighbor] = true;
//                 q.push(neighbor);
//             }
//         }
//     }
// }

// int main() {
//     int n = 5;
//     vector<vector<int>> graph(n);

//     graph[0] = {1, 2};
//     graph[1] = {3};
//     graph[2] = {};
//     graph[3] = {4};
//     graph[4] = {};

//     bfs(0, graph);

//     return 0;
// }