diff options
author | Jack Sangdahl <[email protected]> | 2025-03-10 00:36:13 -0600 |
---|---|---|
committer | Jack Sangdahl <[email protected]> | 2025-03-10 00:36:13 -0600 |
commit | 7c60dee83b436e8e8a667bf9f191beced8de4fc3 (patch) | |
tree | eb7a24ee2067f92245c57bb118e85a1baf15df50 /other/modify_graph_edge_weight.cpp | |
parent | 5d7cdc215e4ba1ec4cbb24c084cccb5e5e641468 (diff) | |
download | leetcode-7c60dee83b436e8e8a667bf9f191beced8de4fc3.tar.gz leetcode-7c60dee83b436e8e8a667bf9f191beced8de4fc3.zip |
chore: move cpp and rust code to directory
Diffstat (limited to 'other/modify_graph_edge_weight.cpp')
-rw-r--r-- | other/modify_graph_edge_weight.cpp | 91 |
1 files changed, 91 insertions, 0 deletions
diff --git a/other/modify_graph_edge_weight.cpp b/other/modify_graph_edge_weight.cpp new file mode 100644 index 0000000..289098f --- /dev/null +++ b/other/modify_graph_edge_weight.cpp @@ -0,0 +1,91 @@ +// 2699. Modify Graph Edge Weights +#include "leetcode.h" + +/* + * you are given an undirected weighted connected graph containing 'n' nodes + * labeled from '0' to 'n - 1' and an integer array 'edges' where 'edges[i] = + * [ai, bi, wi]' indicates that there is an edge between nodes 'ai' and 'bi' + * with weight 'wi'. some edges have a weight of -1 ('wi = -1'), while other + * have a positive weight ('wi > 0'). your task is to modify all edges with a + * weight of -1 by assigning them positive integer values in the range '[1, 2 * + * 10^9]' so that the shortest distance between the nodes 'source' and + * 'destination' becomes equal to an integer 'target'. if there are multiple + * modifications that make the shortest distance equal to 'target', any of them + * are considered correct. return an array containing all edges in any order if + * it is possible to make the shortest to equal 'target', or an empty array if + * it is not possible + */ + +class Solution { + array<int, 2> bfs(vector<vector<array<int, 2>>> &adj, + vector<vector<int>> &edges, int source, int destination, + int target, bool modify) { + priority_queue<array<int, 2>, vector<array<int, 2>>, greater<>> pq; + vector<int> dist(adj.size(), INT_MAX), mod_id(adj.size(), INT_MAX); + pq.push({0, source}); + dist[source] = 0; + while (!pq.empty() && pq.top()[1] != destination) { + auto [d, i] = pq.top(); + pq.pop(); + if (d != dist[i]) + continue; + for (auto [j, edge_id] : adj[i]) { + int w = edges[edge_id][2]; + if (modify || w != -1) + if (dist[j] > d + max(1, w)) { + mod_id[j] = w == -1 ? edge_id : mod_id[i]; + dist[j] = d + max(1, w); + pq.push({d + max(1, w), j}); + } + } + } + return {dist[destination], mod_id[destination]}; + } + +public: + vector<vector<int>> modifiedGraphEdges(int n, vector<vector<int>> &edges, + int source, int destination, + int target) { + vector<vector<array<int, 2>>> adj(n); + for (int i = 0; i < edges.size(); ++i) { + adj[edges[i][0]].push_back({edges[i][1], i}); + adj[edges[i][1]].push_back({edges[i][0], i}); + } + auto [dist, _] = bfs(adj, edges, source, destination, target, false); + if (dist < target) + return {}; + while (true) { + auto [dist, mod_id] = bfs(adj, edges, source, destination, target, true); + if (dist > target) + return {}; + if (dist == target) + break; + edges[mod_id][2] = 1 + target - dist; + } + for (auto &e : edges) + e[2] = e[2] == -1 ? 1 : e[2]; + return edges; + } +}; + +int main() { + Solution obj; + vvd e1 = {{4, 1, -1}, {2, 0, -1}, {0, 3, -1}, {4, 3, -1}}, + e2 = {{0, 1, -1}, {0, 2, 5}}, + e3 = {{1, 0, 4}, {1, 2, 3}, {2, 3, 5}, {0, 3, -1}}; + vvd mge1 = obj.modifiedGraphEdges(5, e1, 0, 1, 5), + mge2 = obj.modifiedGraphEdges(3, e2, 0, 2, 6), + mge3 = obj.modifiedGraphEdges(4, e3, 0, 2, 6); + for (int i = 0; i < mge1.size(); i++) + for (int j = 0; j < mge1[0].size(); j++) + printf("%d ", mge1[i][j]); // expect: [[4,1,1],[2,0,1],[0,3,3],[4,3,1]] + printf("\n"); + for (int i = 0; i < mge2.size(); i++) + for (int j = 0; j < mge2[0].size(); j++) + printf("%d ", mge2[i][j]); // expect: [] + printf("\n"); + for (int i = 0; i < mge3.size(); i++) + for (int j = 0; j < mge3[0].size(); j++) + printf("%d ", mge3[i][j]); // expect: [[1,0,4],[1,2,3],[2,3,5],[0,3,1]] + printf("\n"); +} |