#include <iostream> #include <vector> using namespace std; typedef long long ll; const ll inf = 1e18; const int roz = 1e5 + 10; ll z[roz]; vector <pair <int, ll> > graf[roz]; ll odl[roz]; ll ost[roz]; int dfs(int a, int o) { int i; for(i = 0; i < graf[a].size(); i++) { if(ost[graf[a][i].first] != 0) { odl[graf[a][i].first] = odl[a] + graf[a][i].second; ost[graf[a][i].first] = o; dfs(graf[a][i].first, o); } } } int main() { int n, q, i, j; cin>>n>>q; for(i = 1; i <= n; i++) { cin>>z[i]; } for(i = 1; i <= n - 1; i++) { int a, b; ll c; cin>>a>>b>>c; graf[a].push_back(make_pair(b, c)); graf[b].push_back(make_pair(a, c)); } int akt = 1; for(j = 1; j <= q; j++) { int r; cin>>r; if(r == 1) { int v; ll d; cin>>v>>d; z[v] = d; } else { int a, b; ll d; cin>>a>>b>>d; for(i = 0; i < graf[a].size(); i++) { if(graf[a][i].first == b) graf[a][i] = make_pair(b, d); } for(i = 0; i < graf[b].size(); i++) { if(graf[b][i].first == a) graf[b][i] = make_pair(a, d); } } ost[akt] = j; dfs(akt, j); ll maks = 0; int dok = 0; for(i = 1; i <= n; i++) { if(z[i] - odl[i] > maks) { dok = i; maks = z[i] - odl[i]; } } akt = dok; cout<<akt<<" "; } }
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 | #include <iostream> #include <vector> using namespace std; typedef long long ll; const ll inf = 1e18; const int roz = 1e5 + 10; ll z[roz]; vector <pair <int, ll> > graf[roz]; ll odl[roz]; ll ost[roz]; int dfs(int a, int o) { int i; for(i = 0; i < graf[a].size(); i++) { if(ost[graf[a][i].first] != 0) { odl[graf[a][i].first] = odl[a] + graf[a][i].second; ost[graf[a][i].first] = o; dfs(graf[a][i].first, o); } } } int main() { int n, q, i, j; cin>>n>>q; for(i = 1; i <= n; i++) { cin>>z[i]; } for(i = 1; i <= n - 1; i++) { int a, b; ll c; cin>>a>>b>>c; graf[a].push_back(make_pair(b, c)); graf[b].push_back(make_pair(a, c)); } int akt = 1; for(j = 1; j <= q; j++) { int r; cin>>r; if(r == 1) { int v; ll d; cin>>v>>d; z[v] = d; } else { int a, b; ll d; cin>>a>>b>>d; for(i = 0; i < graf[a].size(); i++) { if(graf[a][i].first == b) graf[a][i] = make_pair(b, d); } for(i = 0; i < graf[b].size(); i++) { if(graf[b][i].first == a) graf[b][i] = make_pair(a, d); } } ost[akt] = j; dfs(akt, j); ll maks = 0; int dok = 0; for(i = 1; i <= n; i++) { if(z[i] - odl[i] > maks) { dok = i; maks = z[i] - odl[i]; } } akt = dok; cout<<akt<<" "; } } |