HDU 2586 LCA Transfer RMQ

Click to open link

Test instructions: Just ask the distance between two nodes

Idea: Another cut a template water problem, do not explain, do not understand the meaning of the variable can see I write this article, explain the comparative details Zoj 3195

#include <vector> #include <stdio.h> #include <string.h> #include <stdlib.h> #include < Iostream> #include <algorithm>using namespace std;typedef long long ll;const int Inf=0x3f3f3f3f;const int maxn=    40010;struct edge{int to,cost; Edge (int a,int b) {to=a;cost=b;}}; Vector<edge>g[maxn];int Dp[maxn*2][20],l[maxn*2],e[maxn*2],dis[maxn],h[maxn];bool vis[maxn];int n,k;void Dfs (int t,int deep) {k++; e[k]=t; L[k]=deep;    H[t]=k;        for (unsigned int i=0;i<g[t].size (); i++) {Edge e=g[t][i];            if (!vis[e.to]) {dis[e.to]=dis[t]+e.cost;            Vis[e.to]=1;            DFS (E.TO,DEEP+1); k++; e[k]=t;        L[k]=deep;    }}}void Rmq_init () {for (int i=1;i<=2*n-1;i++) dp[i][0]=i; for (int i=1, (1<<i) <=2*n-1;i++) {for (int j=1;j+ (1<<i) -1<=2*n-1;j++) {if (L[DP[J][I-1]]&L T            l[dp[j+ (1<< (i-1))][i-1]]) dp[j][i]=dp[j][i-1];        Else dp[j][i]=dp[j+ (1<< (i-1))][i-1];    }}}int RMQ (int le,int ri) {Le=h[le];ri=h[ri];    if (Le>ri) swap (LE,RI);    int kk=0;    while ((1<< (kk+1)) <=ri-le+1) kk++;    if (l[dp[le][kk]]<l[dp[ri-(1&LT;&LT;KK) +1][KK]]) return E[DP[LE][KK]]; else return e[dp[ri-(1&LT;&LT;KK) +1][KK];}    int main () {int t,m,a,b,c;    scanf ("%d", &t);        while (t--) {scanf ("%d%d", &n,&m);        memset (dis,0,sizeof (dis));        memset (vis,0,sizeof (VIS));        for (int i=0;i<maxn;i++) g[i].clear ();            for (int i=0;i<n-1;i++) {scanf ("%d%d%d", &a,&b,&c);            G[a].push_back (Edge (b,c));        G[b].push_back (Edge (a,c));        } k=0;vis[1]=1; DFS (a);        Rmq_init ();            while (m--) {scanf ("%d%d", &a,&b);            int Ans=dis[a]+dis[b]-2*dis[rmq (A, b)];        printf ("%d\n", ans); }} return 0;}

HDU 2586 LCA Transfer RMQ