#include <iostream>
#include <vector>
#include <algorithm>
#include <unordered_set>
using namespace std;
struct find_union{
int n;
vector<int> p;
vector<int> rank;
vector<int> cc_size;
find_union(int n) : n(n), p(vector<int>(n)), rank(vector<int>(n, 0)), cc_size(n, 1){
for(int i = 0; i < n; ++i) p[i] = i;
}
int find(int x){
if(p[x] != x) p[x] = find(p[x]);
return p[x];
}
void onion(int x, int y){
x = find(x);
y = find(y);
if(x == y) return;
if(rank[x] > rank[y]) {
swap(x, y);
}
p[x] = y;
cc_size[y] += cc_size[x];
if(rank[x] == rank[y]) rank[y] += 1;
}
int get_cc_size(int v){
return cc_size[find(v)];
}
void decrement_cc_size(int v){
cc_size[find(v)]--;
}
};
void case1(){
int n, q;
cin >> n >> q;
int id[n + 1];
find_union fu(q + n + 1);
vector<bool> noForSure(q + n + 1, true);
int next_id = n + 1;
for(int i = 0; i < n + 1; ++i)id[i] = i;
for(int i = 0; i < q; ++i){
char type;
cin >> type;
if(type == '+'){
int v, w;
cin >> v >> w;
v = id[v];
w = id[w];
noForSure[v] = false;
noForSure[w] = false;
if(fu.find(v) == fu.find(w)) fu.onion(0, v);
else fu.onion(v, w);
}else if(type == '-'){
int v;
cin >> v;
fu.decrement_cc_size(id[v]);
id[v] = next_id;
++next_id;
}else if(type == '?'){
int v;
cin >> v;
v = id[v];
if(noForSure[v] || fu.get_cc_size(v) == 1){
cout<<'0';
continue;
}
if(fu.find(v) == fu.find(0)) cout << '1';
else cout << '?';
}
}
cout<<'\n';
}
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
case1();
return 0;
}
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 | #include <iostream> #include <vector> #include <algorithm> #include <unordered_set> using namespace std; struct find_union{ int n; vector<int> p; vector<int> rank; vector<int> cc_size; find_union(int n) : n(n), p(vector<int>(n)), rank(vector<int>(n, 0)), cc_size(n, 1){ for(int i = 0; i < n; ++i) p[i] = i; } int find(int x){ if(p[x] != x) p[x] = find(p[x]); return p[x]; } void onion(int x, int y){ x = find(x); y = find(y); if(x == y) return; if(rank[x] > rank[y]) { swap(x, y); } p[x] = y; cc_size[y] += cc_size[x]; if(rank[x] == rank[y]) rank[y] += 1; } int get_cc_size(int v){ return cc_size[find(v)]; } void decrement_cc_size(int v){ cc_size[find(v)]--; } }; void case1(){ int n, q; cin >> n >> q; int id[n + 1]; find_union fu(q + n + 1); vector<bool> noForSure(q + n + 1, true); int next_id = n + 1; for(int i = 0; i < n + 1; ++i)id[i] = i; for(int i = 0; i < q; ++i){ char type; cin >> type; if(type == '+'){ int v, w; cin >> v >> w; v = id[v]; w = id[w]; noForSure[v] = false; noForSure[w] = false; if(fu.find(v) == fu.find(w)) fu.onion(0, v); else fu.onion(v, w); }else if(type == '-'){ int v; cin >> v; fu.decrement_cc_size(id[v]); id[v] = next_id; ++next_id; }else if(type == '?'){ int v; cin >> v; v = id[v]; if(noForSure[v] || fu.get_cc_size(v) == 1){ cout<<'0'; continue; } if(fu.find(v) == fu.find(0)) cout << '1'; else cout << '?'; } } cout<<'\n'; } int main(){ ios_base::sync_with_stdio(0); cin.tie(0); case1(); return 0; } |
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