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| #include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#define MAXN 100010
#define LOG 30
namespace STman {
inline char gc(){
#ifdef ONLINE_JUDGE
static char now[1 << 16], *S, *T;
if (T == S) {T = (S = now) + fread(now, 1, 1 << 16, stdin); if (T == S) return EOF;}
return *S++;
#else
return getchar();
#endif
}
template <typename Tp>
inline void read(Tp &x) {
Tp f = 1;x = 0;
char k = gc();
while (k < '0' || k > '9') {if (k == '-') f = -1;k = gc();}
while (k >= '0' && k <= '9') {x = x * 10 + k - '0';k = gc();}
x = x * f;
}
template <typename Tp>
inline void write(Tp x) {
if (x < 0) putchar('-') , x = -x;
if (x > 9) write(x / 10);
putchar(x % 10 + '0');
}
template <typename Tp>
inline Tp max(Tp a , Tp b) {
if (a > b) return a;
else return b;
}
template <typename Tp>
inline Tp min(Tp a , Tp b) {
if (a < b) return a;
else return b;
}
template <typename Tp>
inline void swap(Tp &a , Tp &b) {
Tp t = a;
a = b;
b = t;
}
template <typename Tp>
inline Tp abs(Tp &a) {
if (a < 0) return -a;
else return a;
}
inline void sp() {
putchar(32);
}
inline void et() {
putchar(10);
}
}
using namespace STman;
struct Edge {
int v, nx;
}e[MAXN];
int head[MAXN], ecnt, dfn[MAXN], in[MAXN], st[MAXN], q, f, g;
int top, num, n, m, x[MAXN], y[MAXN], low[MAXN], tim;
int anc[MAXN << 1][LOG], dep[MAXN << 1], len;
bool vis[MAXN], a[MAXN];
void add(int f, int t) {
e[++ecnt] = (Edge) {t, head[f]};
head[f] = ecnt;
}
void tarjan(int u, int fa) {
dfn[u] = low[u] = ++tim;
st[++top] = u;
for (int i = head[u]; i; i = e[i].nx) {
int v = e[i].v;
if (v == fa) continue;
if (!dfn[v]) {
tarjan(v, u);
low[u] = min(low[u], low[v]);
}
else low[u] = min(low[u], dfn[v]);
}
if (low[u] == dfn[u]) {
int v;
num++;
do {
v = st[top--];
in[v] = num;
} while (u != v);
}
}
void dfs(int u, int p, int d) {
anc[u][0] = p;
dep[u] = d;
for (int i = head[u]; i; i = e[i].nx) {
int to = e[i].v;
if (to == p) continue;
dfs(to, u, d + 1);
}
}
inline void init(int r, int n) {
dfs(r, 0, 1);
for (int j = 1; j < LOG; j++) {
for (int i = 1; i <= n; i++) {
anc[i][j] = anc[anc[i][j - 1]][j - 1];
}
}
}
inline int LCA(int x, int y) {
if (dep[x] < dep[y]) std::swap(x , y);
int h = dep[x] - dep[y];
for (int i = 0; h > 0; i++) {
if (h & 1) x = anc[x][i];
h >>= 1;
}
if (x == y) return x;
for (int i = LOG - 1; i >= 0; i--) {
if (anc[x][i] != anc[y][i]) {
x = anc[x][i];
y = anc[y][i];
}
}
return anc[x][0];
}
int main() {
read(n), read(m);
for (int i = 1; i <= m; i++) {
read(x[i]), read(y[i]);
add(x[i], y[i]);
add(y[i], x[i]);
}
for (int i = 1; i <= n; i++) {
if (!dfn[i]) tarjan(i, -1);
}
memset(vis, 0, sizeof(vis));
memset(head, 0, sizeof(head));
memset(e, 0, sizeof(e));
ecnt = 0;
for (int i = 1; i <= m; i++) {
if (in[x[i]] != in[y[i]]) {
add(in[x[i]], in[y[i]]);
add(in[y[i]], in[x[i]]);
}
}
init(1, num);
read(q);
for (int i = 1; i <= q; i++) {
read(f), read(g);
int ws = 0;
f = in[f];
g = in[g];
int lca = dep[f] + dep[g] - 2 * dep[LCA(f, g)] + 1;
while (lca) {
a[++ws] = lca % 2;
lca /= 2;
}
for (int j = ws; j >= 1; j--) {
write(a[j]);
}
et();
}
}
|
