OpenSoure_Repos/TheAlgorithms-C-Plus-Plus
1
0
Fork 0
mirror of https://hub.njuu.cf/TheAlgorithms/C-Plus-Plus.git synced 2023-10-11 13:05:55 +08:00
Code Issues Packages Projects Releases Wiki Activity

fix: clang-format for dijkstra (#1055)

Browse Source
This commit is contained in:
Filip Hlasek 2020-08-27 07:29:22 -07:00 committed by GitHub
parent 79fb528dad
commit eee5f9495d
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 93 additions and 93 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

186
graph/dijkstra.cpp
View File

@ -26,10 +26,10 @@
#include <cassert> #include <cassert>
#include <iostream> #include <iostream>
#include <limits> #include <limits>
#include <memory>
#include <queue> #include <queue>
#include <utility> #include <utility>
#include <vector> #include <vector>
#include <memory>
constexpr int64_t INF = std::numeric_limits<int64_t>::max(); constexpr int64_t INF = std::numeric_limits<int64_t>::max();
@ -39,31 +39,31 @@ constexpr int64_t INF = std::numeric_limits<int64_t>::max();
*/ */
namespace graph { namespace graph {
/** /**
* @brief Function that add edge between two nodes or vertices of graph * @brief Function that add edge between two nodes or vertices of graph
* *
* @param u any node or vertex of graph * @param u any node or vertex of graph
* @param v any node or vertex of graph * @param v any node or vertex of graph
*/ */
void addEdge(std::vector<std::vector<std::pair<int, int>>> *adj, int u, int v, void addEdge(std::vector<std::vector<std::pair<int, int>>> *adj, int u, int v,
int w) { int w) {
(*adj)[u - 1].push_back(std::make_pair(v - 1, w)); (*adj)[u - 1].push_back(std::make_pair(v - 1, w));
// (*adj)[v - 1].push_back(std::make_pair(u - 1, w)); // (*adj)[v - 1].push_back(std::make_pair(u - 1, w));
} }
/** /**
* @brief Function runs the dijkstra algorithm for some source vertex and * @brief Function runs the dijkstra algorithm for some source vertex and
* target vertex in the graph and returns the shortest distance of target * target vertex in the graph and returns the shortest distance of target
* from the source. * from the source.
* *
* @param adj input graph * @param adj input graph
* @param s source vertex * @param s source vertex
* @param t target vertex * @param t target vertex
* *
* @return shortest distance if target is reachable from source else -1 in * @return shortest distance if target is reachable from source else -1 in
* case if target is not reachable from source. * case if target is not reachable from source.
*/ */
int dijkstra(std::vector<std::vector<std::pair<int, int>>> *adj, int s, int t) { int dijkstra(std::vector<std::vector<std::pair<int, int>>> *adj, int s, int t) {
/// n denotes the number of vertices in graph /// n denotes the number of vertices in graph
int n = adj->size(); int n = adj->size();
@ -74,7 +74,7 @@ namespace graph {
/// first element of pair contains the distance /// first element of pair contains the distance
/// second element of pair contains the vertex /// second element of pair contains the vertex
std::priority_queue<std::pair<int, int>, std::vector<std::pair<int, int>>, std::priority_queue<std::pair<int, int>, std::vector<std::pair<int, int>>,
std::greater<std::pair<int, int>>> std::greater<std::pair<int, int>>>
pq; pq;
/// pushing the source vertex 's' with 0 distance in min heap /// pushing the source vertex 's' with 0 distance in min heap
@ -84,97 +84,97 @@ namespace graph {
dist[s] = 0; dist[s] = 0;
while (!pq.empty()) { while (!pq.empty()) {
/// second element of pair denotes the node / vertex /// second element of pair denotes the node / vertex
int currentNode = pq.top().second; int currentNode = pq.top().second;
/// first element of pair denotes the distance /// first element of pair denotes the distance
int currentDist = pq.top().first; int currentDist = pq.top().first;
pq.pop(); pq.pop();
/// for all the reachable vertex from the currently exploring vertex /// for all the reachable vertex from the currently exploring vertex
/// we will try to minimize the distance /// we will try to minimize the distance
for (std::pair<int, int> edge : (*adj)[currentNode]) { for (std::pair<int, int> edge : (*adj)[currentNode]) {
/// minimizing distances /// minimizing distances
if (currentDist + edge.second < dist[edge.first]) { if (currentDist + edge.second < dist[edge.first]) {
dist[edge.first] = currentDist + edge.second; dist[edge.first] = currentDist + edge.second;
pq.push(std::make_pair(dist[edge.first], edge.first)); pq.push(std::make_pair(dist[edge.first], edge.first));
}
} }
}
} }
if (dist[t] != INF) { if (dist[t] != INF) {
return dist[t]; return dist[t];
} }
return -1; return -1;
} }
} // namespace graph } // namespace graph
/** Function to test the Algorithm */ /** Function to test the Algorithm */
void tests() { void tests() {
std::cout << "Initiatinig Predefined Tests..." << std::endl; std::cout << "Initiatinig Predefined Tests..." << std::endl;
std::cout << "Initiating Test 1..." << std::endl; std::cout << "Initiating Test 1..." << std::endl;
std::vector<std::vector<std::pair<int, int>>> adj1( std::vector<std::vector<std::pair<int, int>>> adj1(
4, std::vector<std::pair<int, int>>()); 4, std::vector<std::pair<int, int>>());
graph::addEdge(&adj1, 1, 2, 1); graph::addEdge(&adj1, 1, 2, 1);
graph::addEdge(&adj1, 4, 1, 2); graph::addEdge(&adj1, 4, 1, 2);
graph::addEdge(&adj1, 2, 3, 2); graph::addEdge(&adj1, 2, 3, 2);
graph::addEdge(&adj1, 1, 3, 5); graph::addEdge(&adj1, 1, 3, 5);
int s = 1, t = 3; int s = 1, t = 3;
assert(graph::dijkstra(&adj1, s - 1, t - 1) == 3); assert(graph::dijkstra(&adj1, s - 1, t - 1) == 3);
std::cout << "Test 1 Passed..." << std::endl; std::cout << "Test 1 Passed..." << std::endl;
s = 4, t = 3; s = 4, t = 3;
std::cout << "Initiating Test 2..." << std::endl; std::cout << "Initiating Test 2..." << std::endl;
assert(graph::dijkstra(&adj1, s - 1, t - 1) == 5); assert(graph::dijkstra(&adj1, s - 1, t - 1) == 5);
std::cout << "Test 2 Passed..." << std::endl; std::cout << "Test 2 Passed..." << std::endl;
std::vector<std::vector<std::pair<int, int>>> adj2( std::vector<std::vector<std::pair<int, int>>> adj2(
5, std::vector<std::pair<int, int>>()); 5, std::vector<std::pair<int, int>>());
graph::addEdge(&adj2, 1, 2, 4); graph::addEdge(&adj2, 1, 2, 4);
graph::addEdge(&adj2, 1, 3, 2); graph::addEdge(&adj2, 1, 3, 2);
graph::addEdge(&adj2, 2, 3, 2); graph::addEdge(&adj2, 2, 3, 2);
graph::addEdge(&adj2, 3, 2, 1); graph::addEdge(&adj2, 3, 2, 1);
graph::addEdge(&adj2, 2, 4, 2); graph::addEdge(&adj2, 2, 4, 2);
graph::addEdge(&adj2, 3, 5, 4); graph::addEdge(&adj2, 3, 5, 4);
graph::addEdge(&adj2, 5, 4, 1); graph::addEdge(&adj2, 5, 4, 1);
graph::addEdge(&adj2, 2, 5, 3); graph::addEdge(&adj2, 2, 5, 3);
graph::addEdge(&adj2, 3, 4, 4); graph::addEdge(&adj2, 3, 4, 4);
s = 1, t = 5; s = 1, t = 5;
std::cout << "Initiating Test 3..." << std::endl; std::cout << "Initiating Test 3..." << std::endl;
assert(graph::dijkstra(&adj2, s - 1, t - 1) == 6); assert(graph::dijkstra(&adj2, s - 1, t - 1) == 6);
std::cout << "Test 3 Passed..." << std::endl; std::cout << "Test 3 Passed..." << std::endl;
std::cout << "All Test Passed..." << std::endl << std::endl; std::cout << "All Test Passed..." << std::endl << std::endl;
} }
/** Main function */ /** Main function */
int main() { int main() {
// running predefined tests // running predefined tests
tests(); tests();
int vertices = int(), edges = int(); int vertices = int(), edges = int();
std::cout << "Enter the number of vertices : "; std::cout << "Enter the number of vertices : ";
std::cin >> vertices; std::cin >> vertices;
std::cout << "Enter the number of edges : "; std::cout << "Enter the number of edges : ";
std::cin >> edges; std::cin >> edges;
std::vector<std::vector<std::pair<int, int>>> adj( std::vector<std::vector<std::pair<int, int>>> adj(
vertices, std::vector<std::pair<int, int>>()); vertices, std::vector<std::pair<int, int>>());
int u = int(), v = int(), w = int(); int u = int(), v = int(), w = int();
while (edges--) { while (edges--) {
std::cin >> u >> v >> w; std::cin >> u >> v >> w;
graph::addEdge(&adj, u, v, w); graph::addEdge(&adj, u, v, w);
} }
int s = int(), t = int(); int s = int(), t = int();
std::cin >> s >> t; std::cin >> s >> t;
int dist = graph::dijkstra(&adj, s - 1, t - 1); int dist = graph::dijkstra(&adj, s - 1, t - 1);
if (dist == -1) { if (dist == -1) {
std::cout << "Target not reachable from source" << std::endl; std::cout << "Target not reachable from source" << std::endl;
} else { } else {
std::cout << "Shortest Path Distance : " << dist << std::endl; std::cout << "Shortest Path Distance : " << dist << std::endl;
} }
return 0; return 0;
} }