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
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
#include <iostream>
#include <vector>
#include <unordered_map>
#include <queue>
#include <set>
using namespace std;
const long long INF_DIST = 10000000000000000;

struct INEdge {
    int x, y, d;
};
struct INQuery {
    int op;
    int in1, in3;
    long long in2;
};

int n, m, q;
vector<INEdge> IE;
vector<INQuery> IQ;

// ================== BRUTE FORCE ============================
void brute_force() {
    vector<unordered_map<int, int>> G(n);
    vector<int> C(n, 0);
    for (const auto& ie : IE) {
        G[ie.x-1][ie.y-1] = ie.d;
        G[ie.y-1][ie.x-1] = ie.d;
    }

    for (const auto& iq : IQ) {
        if (iq.op == 1) {
            int a=iq.in1, b=iq.in2, d=iq.in3;
            G[a-1][b-1] = d;
            G[b-1][a-1] = d;
        }

        else if (iq.op == 2) {
            int a=iq.in1, b=iq.in2;
            G[a-1].erase(b-1);
            G[b-1].erase(a-1);
        }

        else if (iq.op == 3) {
            int v=iq.in1, k=iq.in3;
            long long z=iq.in2;

            vector<long long> dist(n, z+1);
            priority_queue<pair<long long,int>> PQ; // {-dist, vertex}
            dist[v-1] = 0;
            PQ.push({0, v-1});

            while (!PQ.empty()) {
                auto [d, vv] = PQ.top();
                PQ.pop();
                d = -d;
                if (d != dist[vv])
                    continue;
                C[vv] = k;
                for (auto it=G[vv].begin(); it!=G[vv].end(); it++) {
                    long long dd = d + it->second;
                    if (dd < dist[it->first]) {
                        dist[it->first] = dd;
                        PQ.push({-dd, it->first});
                    }
                }
            }
        }

        else {
            int u=iq.in1;
            cout << C[u-1] << '\n';
        }
    }
}

// ====================== STATIC TREE / NO RANGES ===================
vector<vector<int>> G;
vector<int> T;
vector<int> C;

void dfs(int v, int p) {
    for (int nei : G[v])
        if (nei != p) {
            T[nei] = T[v];
            dfs(nei, v);
        }
}

void static_forest_no_ranges() {
    G.clear();
    G.resize(n);
    for (const auto& ie : IE) {
        G[ie.x-1].push_back(ie.y-1);
        G[ie.y-1].push_back(ie.x-1);
    }
    
    // find trees
    T.clear();
    T.resize(n, -1);
    for (int i=0; i<n; i++)
        if (T[i] == -1) {
            T[i] = C.size();
            dfs(i, -1);
            C.push_back(0);
        }

    // queries
    for (const auto& iq : IQ) {
        if (iq.op == 3)
            C[T[iq.in1-1]] = iq.in3;
        else
            cout << C[T[iq.in1-1]] << '\n';
    }
}

// ====================== MAIN =======================
int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    cin >> n >> m >> q;

    IE.resize(m);
    for (auto &ie : IE)
        cin >> ie.x >> ie.y >> ie.d;
    IQ.resize(q);
    for (auto &iq : IQ) {
        cin >> iq.op >> iq.in1;
        if (iq.op != 4) {
            cin >> iq.in2;
            if (iq.op != 2)
                cin >> iq.in3;
        }
    }

    bool tree_changes = false;
    bool range_query = false;
    for (const auto& iq : IQ) {
        if (iq.op==1 || iq.op==2)
            tree_changes = true;
        if (iq.op==3 && iq.in2 != 1000000000000000)
            range_query = true;
    }

    if (!tree_changes && !range_query)
        static_forest_no_ranges();
    else
        brute_force();

    return 0;
}