-
Notifications
You must be signed in to change notification settings - Fork 3
/
2699.cpp
61 lines (57 loc) · 2.14 KB
/
2699.cpp
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
typedef pair<int, int> P;
class Solution {
public:
vector<vector<int>> modifiedGraphEdges(int n, vector<vector<int>>& edges, int source, int destination, int target) {
unordered_map<int, unordered_map<int, int>> mp;
unordered_map<int, unordered_map<int, bool>> invalidEdges;
for (auto& edge : edges) {
int a = edge[0];
int b = edge[1];
int c = edge[2];
if (c == -1) {
invalidEdges[a][b] = true;
invalidEdges[b][a] = true;
c = 1;
}
mp[a][b] = c;
mp[b][a] = c;
}
priority_queue<P, vector<P>, greater<P>> pq;
vector<int> distances1(n, INT_MAX / 3);
pq.push({0, destination});
while (!pq.empty()) {
auto [distance, node] = pq.top();
pq.pop();
if (distances1[node] != INT_MAX / 3) continue;
distances1[node] = distance;
for (auto& [neighbor, weight] : mp[node]) {
if (distances1[neighbor] != INT_MAX / 3) continue;
pq.push({distance + weight, neighbor});
}
}
vector<int> distances(n, INT_MAX / 3);
pq.push({0, source});
while (!pq.empty()) {
auto [distance, node] = pq.top();
pq.pop();
if (distances[node] != INT_MAX / 3) continue;
distances[node] = distance;
if (node == destination && distance != target) return {};
for (auto& [neighbor, weight] : mp[node]) {
if (distances[neighbor] != INT_MAX / 3) continue;
if (invalidEdges[node][neighbor] && distances[node] + weight + distances1[neighbor] < target) {
weight = target - distances[node] - distances1[neighbor];
mp[node][neighbor] = weight;
mp[neighbor][node] = weight;
}
pq.push({distance + weight, neighbor});
}
}
for (auto& edge : edges) {
int a = edge[0];
int b = edge[1];
edge[2] = mp[a][b];
}
return edges;
}
};