1 #include <iostream>
2 #include <algorithm>
3 #include <set>
4 using namespace std;
5 constexpr size_t maxn = 2e5+1;
6 int n, m, q;
7 struct Edge{
8 int from, to, cost;
9 Edge(int from, int to, int cost){
10 this->from = from;
11 this->to = to;
12 this->cost = cost;
13 }
14 };
15 void easy(int,int,int,int);
16
17 struct UFNode{
18 UFNode* parent;
19 UFNode():parent(NULL){}
20 };
21
22 bool cmp(Edge* e1, Edge* e2){
23 return e1->cost < e2->cost;
24 }
25 Edge* edges[maxn];
26 UFNode* find(UFNode* p){
27 if(p->parent == NULL)return p;
28 set<UFNode*> path;
29 while(p->parent != NULL){
30 path.insert(p);
31 p = p->parent;
32 }
33 auto iter = path.begin();
34 while(iter != path.end()){
35 (*iter)->parent = p;
36 iter++;
37 }
38 return p;
39 }
40 void merge(UFNode* p1, UFNode* p2){
41 find(p2)->parent = find(p1);
42 }
43 UFNode point[50001];
44
45 int main(){
46
47 cin >> n >> m >> q;
48 for(int i = 0; i < m; ++ i){
49 int a, b, c;
50 cin >> a >> b >> c;
51 Edge* e = new Edge(a, b, c);
52 edges[i] = e;
53 }
54 //排序
55 sort(edges, edges + m, cmp);
56 for(int i = 0; i < q; ++ i){
57 int l, r, mod, c;
58 cin >> l >> r >> mod >> c;
59 easy(l, r, mod, c);
60 }
61 return 0;
62 }
63
64
65 void easy(int l, int r, int mod, int c){
66 for(int j = 0; j <= n; ++ j){
67 point[j].parent = NULL;
68 }
69 for(int i = 0; i < m; ++ i){
70 Edge* pEdge = edges[i];
71 int from = pEdge->from;
72 int to = pEdge->to;
73 int cost = pEdge->cost;
74
75 if(find(&point[from]) == find(&point[to]))//已经在一颗树上
76 continue;
77 else
78 merge(&point[from], &point[to]);
79 //if n-1 者最小生成数已经完成
80 UFNode* parent = NULL;
81 bool isok = true;
82 for(int j = l; j <= r; ++ j){
83 if(j%mod == c){
84 if(parent == NULL){
85 parent = find(&point[j]);
86 }
87 else{
88 if(parent != find(&point[j])){
89 isok = false;
90 break;
91 }
92 }
93 }
94 }
95 if(isok){
96 cout << cost << endl;
97 break;
98 }
99 }
100 }
