OJ-Problems-Source/HDOJ/4547_autoAC.cpp

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#include <iostream>
#include <cstdio>
#include <string>
#include <map>
#include <cstring>
using namespace std;
const int MAX_ = 400010;
map<string,int>mp;
struct point {
int to,next, num;
} edge[MAX_], qedge[MAX_];
struct query {
int u,v,lca;
} q[MAX_];
int V[MAX_], head[MAX_], d[MAX_], fa[MAX_], ind[MAX_];
bool vis[MAX_];
int M,L, T;
int n, m;
void adde(int from,int to,int c) {
edge[M].to = to;
edge[M].num = c;
edge[M].next = V[from];
V[from] = M++;
}
void addq(int from,int to,int c) {
qedge[L].to = to;
qedge[L].num = c;
qedge[L].next = head[from];
head[from] = L++;
}
int find(int x) {
if(fa[x] == x)return fa[x];
else return fa[x] = find(fa[x]);
}
void dfs(int k,int pri,int x) {
d[x] = k;
for(int i = V[x]; i != -1; i = edge[i].next) {
if(edge[i].to != pri) {
dfs(k+1,x,edge[i].to);
}
}
}
void tarjan(int x) {
fa[x] = x;
vis[x] = 1;
for(int i = V[x]; i != -1; i = edge[i].next) {
if(!vis[edge[i].to]) {
tarjan(edge[i].to);
fa[edge[i].to] = x;
}
}
for(int i = head[x]; i != -1; i = qedge[i].next) {
if(vis[qedge[i].to]) {
q[qedge[i].num].lca = find(qedge[i].to);
}
}
}
void solve() {
for(int i = 1; i <= n; i++) {
if(ind[i] == 0) {
dfs(0,-1,i);
tarjan(i);
break;
}
}
}
int capture(char s[]) {
if(mp.find(s) == mp.end()) {
return mp[s] = ++T;
} else return mp[s];
}
void init() {
memset(V,-1,sizeof(V));
memset(head,-1,sizeof(head));
memset(ind,0,sizeof(ind));
memset(vis,0,sizeof(vis));
M = L = T = 0;
mp.clear();
for(int i = 0; i <= n; i++) {
fa[i] = i;
}
}
void read() {
int s,t;
char c1[50],c2[50];
for(int i = 1; i < n; i++) {
scanf("%s",c1);
scanf("%s",c2);
t = capture(c1);
s = capture(c2);
adde(s,t,1);
adde(t,s,1);
ind[t]++;
}
for(int i = 0; i < m; i++) {
scanf("%s",c1);
scanf("%s",c2);
t = capture(c1);
s = capture(c2);
addq(s,t,i);
addq(t,s,i);
q[i].u = t;
q[i].v = s;
}
}
void print_ans() {
for(int i = 0; i < m; i++) {
int t;
t = d[q[i].u] - d[q[i].lca];
if(q[i].v != q[i].lca) {
t++;
}
if(q[i].u == q[i].v) t = 0;
printf("%d\n",t);
}
}
int main() {
int Case;
scanf("%d",&Case);
while(Case--) {
scanf("%d%d",&n,&m);
init();
read();
solve();
print_ans();
}
return 0;
}