#include <bits/stdc++.h>
#define MAX 200010
using namespace std;
int n, m, q, pai[MAX], sz[MAX], maxi, h[MAX], anc[MAX][30], bla[MAX][2], mark[MAX];
vector < pair <int,int> > g[MAX];
void init(int x){
for(int i=1 ; i<=x ; i++){
pai[i] = i;
sz[i]=1;
h[i] = -1;
}
return;
}
int find(int x){
if(pai[x] == x) return x;
return find(pai[x]);
}
void join(int x, int y, int c){
x = find(x), y = find(y);
if(x == y) return;
if(sz[x] > sz[y]) swap(x,y);
pai[x] = y;
sz[y] += sz[x];
g[x].push_back(make_pair(y,c));
g[y].push_back(make_pair(x,c));
return;
}
void dfs(int x){
for(int i=0 ; i<g[x].size() ; i++){
int v = g[x][i].first;
if(h[v] == -1){
h[v] = h[x]+1;
anc[v][0] = pai[v];
dfs(v);
}
}
}
int lca(int x, int y){
if(h[x] > h[y]) swap(x,y);
for(int i=24 ; i>=0 ; i--){
if(h[y] - (1 << i) >= h[x]) y = anc[y][i];
}
if(x == y) return x;
for(int i=24 ; i>=0 ; i--){
if(anc[x][i] != anc[y][i]){
x = anc[x][i];
y = anc[y][i];
}
}
return anc[x][0];
}
int main(){
ios::sync_with_stdio(false); cin.tie(0);
cin >> n >> m >> q;
init(n);
for(int i=m ; i>=1 ; i--){
for(int j=i ; j<=n ; j+=i){
if(__gcd(i, j) == i) join(i, j, m-i+1);
}
}
for(int i=1 ; i<=n ; i++){
int k = find(i);
if(mark[k] == 0) {
mark[k] = 1;
h[k] = 0;
dfs(k);
}
}
for(int i=1 ; i<25 ; i++){
for(int j=1 ; j<=n ; j++){
anc[j][i] = anc[anc[j][i-1]][i-1];
}
}
for(int i=0 ; i<q ; i++){
int a, b;
cin >> a >> b;
bla[i][0] = a;
bla[i][1] = b;
}
for(int i=0 ; i<q ; i++){
int maxa=0, maxb=0;
int a = bla[i][0];
int b = bla[i][1];
int l = lca(a,b);
//cout << "lca:" << l << endl;
while(a != l){
if(pai[a] == a){
maxa = -1;
break;
}
for(int i=0 ; i<g[a].size() ; i++){
if(g[a][i].first == pai[a]){
maxa = max(maxa, g[a][i].second);
}
}
a = pai[a];
}
while(b != l){
if(pai[b] == b){
maxb = -1;
break;
}
for(int i=0 ; i<g[b].size() ; i++){
if(g[b][i].first == pai[b]){
maxa = max(maxa, g[b][i].second);
}
}
b = pai[b];
}
maxi = max(maxa, maxb);
if(maxa == -1 || maxb == -1) maxi=-1;
cout << maxi << endl;
}
return 0;
}
Compilation message
pictionary.cpp: In function 'void dfs(int)':
pictionary.cpp:46:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
46 | for(int i=0 ; i<g[x].size() ; i++){
| ~^~~~~~~~~~~~
pictionary.cpp: In function 'int main()':
pictionary.cpp:141:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
141 | for(int i=0 ; i<g[a].size() ; i++){
| ~^~~~~~~~~~~~
pictionary.cpp:159:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
159 | for(int i=0 ; i<g[b].size() ; i++){
| ~^~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
10 ms |
5076 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
29 ms |
5304 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
97 ms |
5888 KB |
Output is correct |
2 |
Correct |
100 ms |
6448 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
155 ms |
6388 KB |
Output is correct |
2 |
Correct |
135 ms |
6952 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
79 ms |
9324 KB |
Output is correct |
2 |
Correct |
80 ms |
9868 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
88 ms |
10952 KB |
Output is correct |
2 |
Correct |
106 ms |
12376 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
139 ms |
13616 KB |
Output is correct |
2 |
Correct |
99 ms |
14432 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
156 ms |
16388 KB |
Output is correct |
2 |
Correct |
182 ms |
18972 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
219 ms |
19344 KB |
Output is correct |
2 |
Correct |
225 ms |
22508 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
251 ms |
23228 KB |
Output is correct |
2 |
Correct |
245 ms |
24636 KB |
Output is correct |