結果
| 問題 |
No.470 Inverse S+T Problem
|
| コンテスト | |
| ユーザー |
 rogi52
|
| 提出日時 | 2021-08-15 06:38:44 |
| 言語 | C++14 (gcc 13.3.0 + boost 1.87.0) |
| 結果 |
WA
|
| 実行時間 | - |
| コード長 | 4,795 bytes |
| コンパイル時間 | 2,555 ms |
| コンパイル使用メモリ | 193,768 KB |
| 実行使用メモリ | 5,248 KB |
| 最終ジャッジ日時 | 2024-12-22 14:06:23 |
| 合計ジャッジ時間 | 3,728 ms |
|
ジャッジサーバーID （参考情報） |
judge5 / judge1 |
（要ログイン）
| ファイルパターン | 結果 |
|---|---|
| sample | AC * 3 WA * 1 |
| other | AC * 14 WA * 13 |
コンパイルメッセージ
main.cpp: In function 'int main()':
main.cpp:126:51: warning: narrowing conversion of '(((int)(& U.std::vector<std::__cxx11::basic_string<char> >::operator[](((std::vector<std::__cxx11::basic_string<char> >::size_type)i)))->std::__cxx11::basic_string<char>::operator[](1)) + ((int)(& U.std::vector<std::__cxx11::basic_string<char> >::operator[](((std::vector<std::__cxx11::basic_string<char> >::size_type)i)))->std::__cxx11::basic_string<char>::operator[](2)))' from 'int' to 'char' [-Wnarrowing]
126 | si = string{U[i][0]}, ti = string{U[i][1] + U[i][2]};
main.cpp:126:51: warning: narrowing conversion of '(((int)(& U.std::vector<std::__cxx11::basic_string<char> >::operator[](((std::vector<std::__cxx11::basic_string<char> >::size_type)i)))->std::__cxx11::basic_string<char>::operator[](1)) + ((int)(& U.std::vector<std::__cxx11::basic_string<char> >::operator[](((std::vector<std::__cxx11::basic_string<char> >::size_type)i)))->std::__cxx11::basic_string<char>::operator[](2)))' from 'int' to 'char' [-Wnarrowing]
main.cpp:127:51: warning: narrowing conversion of '(((int)(& U.std::vector<std::__cxx11::basic_string<char> >::operator[](((std::vector<std::__cxx11::basic_string<char> >::size_type)j)))->std::__cxx11::basic_string<char>::operator[](1)) + ((int)(& U.std::vector<std::__cxx11::basic_string<char> >::operator[](((std::vector<std::__cxx11::basic_string<char> >::size_type)j)))->std::__cxx11::basic_string<char>::operator[](2)))' from 'int' to 'char' [-Wnarrowing]
127 | sj = string{U[j][0]}, tj = string{U[j][1] + U[j][2]};
main.cpp:127:51: warning: narrowing conversion of '(((int)(& U.std::vector<std::__cxx11::basic_string<char> >::operator[](((std::vector<std::__cxx11::basic_string<char> >::size_type)j)))->std::__cxx11::basic_string<char>::operator[](1)) + ((int)(& U.std::vector<std::__cxx11::basic_string<char> >::operator[](((std::vector<std::__cxx11::basic_string<char> >::size_type)j)))->std::__cxx11::basic_string<char>::operator[](2)))' from 'int' to '
ソースコード
#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (n); i++)
using namespace std;
typedef long long ll;
struct scc_graph {
int _n;
struct edge {
int to;
};
vector<pair<int,edge>> edges;
template < class E > struct csr {
vector<int> start;
vector< E > elist;
csr(int n, const vector<pair<int,E>> &edges)
: start(n + 1), elist(edges.size()) {
for(auto e : edges) start[e.first + 1]++;
for(int i = 1; i <= n; i++) start[i] += start[i - 1];
auto counter = start;
for(auto e : edges) elist[counter[e.first]++] = e.second;
}
};
scc_graph(int n) : _n(n) {}
scc_graph() : _n(0) {}
int num_vertices() { return _n; }
void add_edge(int from, int to) {
int n = num_vertices();
assert(0 <= from && from < n);
assert(0 <= to && to < n);
edges.push_back({from, {to}});
}
// return pair of (# of scc, scc id)
pair<int, vector<int>> scc_ids() {
auto g = csr<edge>(_n, edges);
int now_ord = 0, group_num = 0;
vector<int> visited, low(_n), ord(_n, -1), ids(_n);
visited.reserve(_n);
auto dfs = [&](auto self, int v) -> void {
low[v] = ord[v] = now_ord++;
visited.push_back(v);
for(int i = g.start[v]; i < g.start[v + 1]; i++){
auto to = g.elist[i].to;
if(ord[to] == -1){
self(self, to);
low[v] = min(low[v], low[to]);
}else{
low[v] = min(low[v], ord[to]);
}
}
if(low[v] == ord[v]){
while(true){
int u = visited.back();
visited.pop_back();
ord[u] = _n;
ids[u] = group_num;
if(u == v) break;
}
group_num++;
}
};
for(int i = 0; i < _n; i++) if(ord[i] == -1) dfs(dfs, i);
for(auto &x : ids) x = group_num - 1 - x;
return {group_num, ids};
}
vector<vector<int>> scc() {
auto ids = scc_ids();
int group_num = ids.first;
vector<int> counts(group_num);
for(auto x : ids.second) counts[x]++;
vector<vector<int>> groups(ids.first);
for(int i = 0; i < group_num; i++) groups[i].reserve(counts[i]);
for(int i = 0; i < _n; i++) groups[ids.second[i]].push_back(i);
return groups;
}
};
struct two_sat {
public:
two_sat() : _n(0), scc(0) {}
two_sat(int n) : _n(n), _answer(n), scc(2 * n) {}
void add_clause(int i, bool f, int j, bool g) {
assert(0 <= i && i < _n);
assert(0 <= j && j < _n);
scc.add_edge(2 * i + (f ? 0 : 1), 2 * j + (g ? 1 : 0));
scc.add_edge(2 * j + (g ? 0 : 1), 2 * i + (f ? 1 : 0));
}
bool satisfiable() {
auto id = scc.scc_ids().second;
for(int i = 0; i < _n; i++){
if(id[2 * i] == id[2 * i + 1]) return false;
_answer[i] = id[2 * i] < id[2 * i + 1];
}
return true;
}
vector<bool> answer() { return _answer; }
private:
int _n;
vector<bool> _answer;
scc_graph scc;
};
int main(){
cin.tie(0);
ios::sync_with_stdio(0);
int N; cin >> N;
if(N >= 55){ cout << "Impossible" << endl; return 0; }
vector<string> U(N);
rep(i,N) cin >> U[i];
two_sat ts(N);
rep(i,N)rep(j,i){
// U[i] <-> U[j]
string si,ti,sj,tj;
si = string{U[i][0]}, ti = string{U[i][1] + U[i][2]};
sj = string{U[j][0]}, tj = string{U[j][1] + U[j][2]};
if(si == sj || ti == tj) ts.add_clause(i, true, j, true);
si = string{U[i][0] + U[i][1]}, ti = string{U[i][2]};
sj = string{U[j][0]}, tj = string{U[j][1] + U[j][2]};
if(si == tj && ti == sj) ts.add_clause(i, false, j, true);
si = string{U[i][0]}, ti = string{U[i][1] + U[i][2]};
sj = string{U[j][0] + U[j][1]}, tj = string{U[j][2]};
if(si == tj && ti == sj) ts.add_clause(i, true, j, false);
si = string{U[i][0] + U[i][1]}, ti = string{U[i][2]};
sj = string{U[j][0] + U[j][1]}, tj = string{U[j][2]};
if(si == sj || ti == tj) ts.add_clause(i, false, j, false);
}
if(!ts.satisfiable()){
cout << "Impossible" << endl;
}else{
auto ans = ts.answer();
rep(i,N){
cout << U[i][0];
if(!ans[i]){
cout << " " << U[i][1];
}else{
cout << U[i][1] << " ";
}
cout << U[i][2] << endl;
}
}
}