POJ-1703 Find them, Catch them
并查集
数组建两倍于n的长度,分为两段,两段对应位置属于同一个人
D
时:
将第一段的p
和第二段的q
相互连接,同时第一段的q
和第二段的p
相互连接,代表 p
、q
属于不同帮派。
A
时:
先判断在第一段内 p
、q
是否相互连接,如果连接则一定属于同一帮派,因为 p
、q
必定以某个敌对帮派的人物为桥梁才建立的连接。
如果不相连接则再判断 p
、q + n
是否相连接,如果连接则一定属于不同帮派
如果上述都不满足则 p
、q
关系不确定
Code
/**
* author: Akvicor
* created: 2019-06-13 21-00-16
**/
#include <cstdio>
#include <cstring>
#include <iomanip>
#include <ctime>
#include <algorithm>
#include <iostream>
#include <string>
#include <vector>
#include <stack>
#include <bitset>
#include <complex>
#include <cstdlib>
#include <cmath>
#include <set>
#include <list>
#include <deque>
#include <map>
#include <queue>
using namespace std;
#ifdef DEBUG
string to_string(string s) {
return '"' + s + '"';
}
string to_string(const char* s) {
return to_string((string) s);
}
string to_string(bool b) {
return (b ? "true" : "false");
}
template <typename A, typename B>
string to_string(pair<A, B> p) {
return "(" + to_string(p.first) + ", " + to_string(p.second) + ")";
}
template <typename A>
string to_string(A v) {
bool first = true;
string res = "{";
for (const auto &x : v) {
if (!first) {
res += ", ";
}
first = false;
res += to_string(x);
}
res += "}";
return res;
}
void debug_out() { cerr << endl; }
template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
cerr << " " << to_string(H);
debug_out(T...);
}
#endif
#ifdef DEBUG
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#else
#define debug(...) 17
#endif
#ifdef DEBUG
#define FAST_IO 17
#define cout cout << "-->"
#else
#define FAST_IO ios::sync_with_stdio(false);cin.tie(0);cout.tie(0)
#define endl '\n'
#endif
#define LL long long
#define ULL unsigned long long
#define rep(i, n) for(int i = 0; i < (n); ++i)
#define reep(i, n) for(int i = 0; i <= (n); ++i)
#define lop(i, a, n) for(int i = a; i < (n); ++i)
#define loop(i, a, n) for(int i = a; i <= (n); ++i)
#define ALL(v) (v).begin(), (v).end()
#define PB push_back
#define VI vector<int>
#define PII pair<int,int>
#define FI first
#define SE second
#define SZ(x) ((int)(x).size())
const double EPS = 1e-6;
const double PI = acos(-1.0);
const int INF = 0x3f3f3f3f;
const LL LINF = 0x7f7f7f7f7f7f7f7f;
const int MAXN = (int)1e6 + 10;
const int MOD = (int)1e9 + 7;
class UnionFind{
private:
int * parent;
int * rank;
int count;
public:
UnionFind(int n){
n *= 2;
n += 10;
parent = new int[n];
rank = new int[n];
this->count = n;
for(int i = 0; i < n; ++i){
parent[i] = i;
rank[i] = 1;
}
}
~UnionFind(){
delete[] parent;
delete[] rank;
}
int find(int p){
while(p != parent[p]){
p = parent[p];
}
return p;
}
bool isConnected(int p, int q){
return find(p) == find(q);
}
void unionElements(int p, int q){
int pRoot = find(p);
int qRoot = find(q);
if(pRoot == qRoot) return;
if(rank[pRoot] < rank[qRoot]){
parent[pRoot] = qRoot;
}else if(rank[qRoot] < rank[pRoot]){
parent[qRoot] = pRoot;
}else{
parent[pRoot] = qRoot;
rank[qRoot] += 1;
}
}
};
int t, n, m, p, q;
char c;
int main(){
//FAST_IO;
//cin >> t;
scanf("%d\n", &t);
while(t--){
//cin >> n >> m;
scanf("%d %d\n", &n, &m);
UnionFind uf = UnionFind(n);
while(m--){
//cin >> c >> p >> q;
scanf("%c %d %d\n", &c, &p, &q);
if(c == 'D'){
uf.unionElements(p, n+q);
uf.unionElements(q, n+p);
}else{
if(uf.isConnected(p, q))
cout << "In the same gang." << endl;
else if(uf.isConnected(p, n+q))
cout << "In different gangs." << endl;
else cout << "Not sure yet." << endl;
}
}
}
return 0;
}