Common ancestor of template nearest

LCA Tarjan off-line algorithm

On-line algorithm for LCA transfer RMQ

#include <cstdio> #include <cstring> #include <algorithm>using namespace std;const int maxn = 200010; struct Edge{int u, V, W, next;} EDGES[MAXN*2], E[maxn];int e[maxn*2], h[maxn*2], i[maxn*2], L[MAXN], r[maxn];int dp[maxn*2][40];int cnt, clock, Dfn;int F Irst[maxn];int a[maxn<<2];int b[maxn];int add[maxn<<2];int degree[maxn];int vis[maxn];void AddEdge (int u, int V, int w) {edges[cnt].u = U;EDGES[CNT].V = V;EDGES[CNT].W = W;edges[cnt].next = First[u];first[u] = cnt++;edges[cnt].u = V;EDGES[CNT].V = U;EDGES[CNT].W = W;edges[cnt].next = First[v];first[v] = cnt++;} void Dfs (int u, int fa, int dep) {E[++clock] = u; H[clock] = dep;i[u] = clock; L[u] = ++DFN;B[DFN] = u;for (int i = first[u]; I! = 1; i = edges[i].next) {int v = edges[i].v;if (v = = FA) continue;if (Vis[v] ) Continue;vis[v] = True;dfs (V, U, dep+1); E[++clock] = u; H[clock] = dep;} R[u] = DFN;} void Rmq_init (int n) {for (int i = 1; I <= n; i++) dp[i][0] = i;for (int j = 1; (1<<j) <= N; J + +) for (int i = 1; i+ (1&LT;&LT;J)-1 <= N; i++) {if (H[dp[i][j-1]] < h[dp[i+ (1<< (j-1))][j-1]]) dp[i][j] = dp[i][j-1];elsedp[i][j] = dp[i+ (1<< (j-1)) ][J-1];}} int RMQ (int l, int r) {L = I[l], r = i[r];if (L > R) Swap (L, r); int len = r-l+1, k = 0;while ((1<<k) <= len) k++;k- -;if (H[dp[l][k]] < h[dp[r-(1<<k) +1][k]] return E[dp[l][k]];elsereturn e[dp[r-(1<<k) +1][k]];}

LCA Multiplication method

#include <cstdio> #include <cstring> #include <algorithm>using namespace std;const int maxn = 20010; const int INF = 999999999;int anc[maxn][16], Maxcost[maxn][16];int FA[MAXN], L[MAXN], COST[MAXN], Vis[maxn];int N, M;int F IRST[MAXN], cnt;struct edge{int u, V, next;} e[maxn*2];void Addedge (int u, int v) {e[cnt].v = V;e[cnt].next = First[u];first[u] = CNT++;E[CNT].V = U;e[cnt].next = First [V];first[v] = cnt++;} void Pre () {for (int i = 1; I <= n; i++) {anc[i][0] = Fa[i]; maxcost[i][0] = cost[i];for (int j = 1; (1&LT;&LT;J) < n; J + +) anc[i][j] = 1;} for (int j = 1; (1&LT;&LT;J) < n; J + +) for (int i = 1; I <= n; i++) if (anc[i][j-1]! =-1) {int a = Anc[i][j-1];anc[i][j] = anc[a][j-1];maxcost[i][j] = max (ma Xcost[i][j-1], maxcost[a][j-1]);}} int query (int p, int q) {int tmp, log, i;if (L[p] < l[q]) swap (p, q); for (log = 1; (1<<log) <= l[p]; log++); Log--;int ans =-inf;for (int i = log; I >= 0; i--) if (L[p]-(1<<i) >= l[q]) {ans = max (ans, maxcost[p][i ]);p = ANC[P] [i];}  if (p = = q) return ans;for (int i = log; I >= 0; i--) {if (anc[p][i]! = 1 && anc[p][i]! = Anc[q][i]) {ans = max (ans, Maxcost[p][i]); ans = max (ans, maxcost[q][i]);p = Anc[p][i];q = Anc[q][i];}} ans = max (ans, cost[p]); ans = max (ans, cost[q); return ans;} void Dfs (int u) {for (int i = first[u]; I! = 1; i = e2[i].next) {int v = e[i].v;if (Vis[v]) continue;vis[v] = 1;fa[v] = u; L[V] = L[u]+1;dfs (v);}}

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Common ancestor of template nearest