Submission #102079

#TimeUsernameProblemLanguageResultExecution timeMemory
102079aintaDesignated Cities (JOI19_designated_cities)C++17
100 / 100
836 ms48708 KiB
#include<cstdio> #include<algorithm> #include<vector> #define N_ 201000 #define SZ 262144 #define pii pair<int,int> #define X first #define Y second using namespace std; vector<int>E[N_]; int n, chk[N_], cnt; long long S[N_], Far[N_], Res[N_]; struct Edge { int e, l; }Ed[N_*2]; void Add_Edge(int a, int b, int c) { E[a].push_back(cnt); Ed[cnt++] = { b,c }; } void DFS1(int a, int pp) { for (auto &t : E[a]) { int x = Ed[t].e, l = Ed[t].l; if (x == pp)continue; DFS1(x, a); Far[a] = max(Far[a], Far[x] + l); S[a] += S[x] + l; } } void DFS2(int a, int pp, long long f) { int pv1 = -1, pv2 = -1; long long f1 = 0, f2 = 0; Far[a] = max(Far[a], f); for (auto &t : E[a]) { int x = Ed[t].e, l = Ed[t].l; if (x == pp)continue; S[x] = S[a] - l + Ed[t ^ 1].l; if (f1 <= Far[x] + l) { pv2 = pv1, f2 = f1; pv1 = x, f1 = Far[x] + l; } else if (f2 <= Far[x] + l) { pv2 = x, f2 = Far[x] + l; } } for (auto &t : E[a]) { int x = Ed[t].e, l = Ed[t].l; if (x == pp)continue; if (x == pv1) { DFS2(x, a, Ed[t ^ 1].l + max(f2,f)); } else { DFS2(x, a, Ed[t ^ 1].l + max(f1,f)); } } } int Num[N_], End[N_], ReNum[N_], par[N_], pL[N_]; long long DD[N_]; struct Tree { long long Mx[SZ + SZ], K[SZ + SZ]; void UDT(int nd) { Mx[nd] = max(Mx[nd * 2], Mx[nd * 2 + 1]); } void init(int nd, int b, int e) { K[nd] = 0; if (b == e) { Mx[nd] = DD[ReNum[b]]; return; } int m = (b + e) >> 1; init(nd * 2, b, m); init(nd * 2 + 1, m + 1, e); UDT(nd); } void Add2(int nd, long long x) { Mx[nd] += x; K[nd] += x; } void Spread(int nd) { Add2(nd * 2, K[nd]); Add2(nd * 2 + 1, K[nd]); K[nd] = 0; } void Add(int nd, int b, int e, int s, int l, long long x) { if (s > l)return; if (b == s && e == l) { Add2(nd, x); return; } int m = (b + e) >> 1; Spread(nd); if (s <= m)Add(nd * 2, b, m, s, min(m, l), x); if (l > m)Add(nd * 2 + 1, m + 1, e, max(m + 1, s), l, x); UDT(nd); } int Find(int nd, int b, int e) { if (Mx[nd] == 0)return 0; if (b == e)return ReNum[b]; int m = (b + e) >> 1; Spread(nd); if (Mx[nd * 2] == Mx[nd])return Find(nd * 2, b, m); return Find(nd * 2 + 1, m + 1, e); } }TT; void DFS3(int a, int pp, long long d) { Num[a] = ++cnt; ReNum[cnt] = a; DD[a] = d; par[a] = pp; for (auto &t : E[a]) { int x = Ed[t].e, l = Ed[t].l; if (x == pp)continue; pL[x] = l; DFS3(x, a, d+l); } End[a] = cnt; } int main() { //freopen("input.txt", "r", stdin); int i, a, b, c, d; scanf("%d", &n); for (i = 1; i < n; i++) { scanf("%d%d%d%d", &a, &b, &c, &d); Add_Edge(a, b, c); Add_Edge(b, a, d); } DFS1(1, 0); DFS2(1, 0, 0); for (i = 1; i <= n; i++)Res[i] = 1e18; for (i = 1; i <= n; i++)Res[1] = min(Res[1], S[i]); int pv = -1; for (i = 1; i <= n; i++) { if (Res[2] > S[i] - Far[i]) { Res[2] = S[i] - Far[i]; pv = i; } } int root = pv; cnt = 0; DFS3(root, 0, 0); TT.init(1, 1, n); for (i = 1; i <= n; i++)chk[i] = 0; chk[root] = 1; long long ss = S[root]; for (i = 2; i <= n; i++) { ss -= TT.Mx[1]; Res[i] = min(Res[i], ss); int a = TT.Find(1, 1, n); if (!a) continue; while (!chk[a]) { TT.Add(1, 1, n, Num[a], End[a], -pL[a]); chk[a] = 1; a = par[a]; } } int Q; scanf("%d", &Q); while (Q--) { scanf("%d", &a); printf("%lld\n", Res[a]); } }

Compilation message (stderr)

designated_cities.cpp: In function 'void DFS2(int, int, long long int)':
designated_cities.cpp:46:20: warning: unused variable 'l' [-Wunused-variable]
   int x = Ed[t].e, l = Ed[t].l;
                    ^
designated_cities.cpp:30:16: warning: variable 'pv2' set but not used [-Wunused-but-set-variable]
  int pv1 = -1, pv2 = -1;
                ^~~
designated_cities.cpp: In function 'int main()':
designated_cities.cpp:120:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &n);
  ~~~~~^~~~~~~~~~
designated_cities.cpp:122:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d%d%d", &a, &b, &c, &d);
   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~
designated_cities.cpp:157:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &Q);
  ~~~~~^~~~~~~~~~
designated_cities.cpp:159:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d", &a);
   ~~~~~^~~~~~~~~~
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