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OI-codes/Luogu/P1341/P1341.cpp

79 lines
1.2 KiB
C++

#include <iostream>
#include <cstring>
#include <set>
using std::cin;
using std::cout;
const char endl = '\n';
const int N = 1005;
int n, cnt, s, t, deg[N], ans[N];
int g[N][N];
std::set<char> nodes;
void dfs(char u) {
for (int i = 1; i <= 128; i++) {
if (g[u][i]) {
g[u][i]--;
g[i][u]--;
dfs(i);
}
}
ans[++cnt] = u;
}
int main() {
std::ios::sync_with_stdio(false);
cin.tie(nullptr);
cin >> n;
for (int i = 1; i <= n; i++) {
char u, v;
cin >> u >> v;
g[u][v]++, g[v][u]++;
deg[u]++, deg[v]++;
nodes.insert(u);
nodes.insert(v);
}
int x = 0;
t = *nodes.rbegin();
for (const char &node : nodes) {
if (deg[node] & 1) {
x++;
if (!s) s = node;
}
}
if (!s) s = *nodes.begin();
if (x && x != 2) {
cout << "No Solution" << endl;
exit(0);
}
dfs(s);
if (cnt <= n) {
cout << "No Solution" << endl;
} else {
for (int i = cnt; i; i--) {
cout << (char)(ans[i]);
}
cout << endl;
}
return 0;
}