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Diffstat (limited to 'modify_graph_edge_weight.cpp')
-rw-r--r-- | modify_graph_edge_weight.cpp | 91 |
1 files changed, 0 insertions, 91 deletions
diff --git a/modify_graph_edge_weight.cpp b/modify_graph_edge_weight.cpp deleted file mode 100644 index 0656f5e..0000000 --- a/modify_graph_edge_weight.cpp +++ /dev/null @@ -1,91 +0,0 @@ -// 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(int) 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(int) 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"); -} |