#include <stdlib.h> #include <time.h> #include <cassert> #include <cstdio> #include <set> #include <string> #include <vector> using namespace std; const int MAXN = 100000 + 5; int n; char color[MAXN]; int g[MAXN][2]; string s, t; set<string> visited; bool dfs(string s) { if (visited.find(s) != visited.end()) return false; if(s == t) return true; visited.insert(s); for (int i = 0; i < n-1; i++) { int u = g[i][0]; int v = g[i][1]; if (s[u] == s[v]) continue; int tmp = s[u]; s[u] = s[v]; if(dfs(s)) return true; s[u] = tmp; tmp = s[v]; s[v] = s[u]; if(dfs(s)) return true;; s[v] = tmp; } return false; } bool solve() { visited.clear(); scanf("%d", &n); scanf("%s\n%", color); s = string(color); scanf("%s\n%", color); t = string(color); for (int i = 0; i < n - 1; i++) { int a, b; scanf("%d %d", &a, &b); a--; b--; g[i][0] = a; g[i][1] = b; } return dfs(s); } int main() { int t; scanf("%d", &t); for (int i = 0; i < t; i++) printf("%s\n", solve() ? "TAK" : "NIE"); }
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 | #include <stdlib.h> #include <time.h> #include <cassert> #include <cstdio> #include <set> #include <string> #include <vector> using namespace std; const int MAXN = 100000 + 5; int n; char color[MAXN]; int g[MAXN][2]; string s, t; set<string> visited; bool dfs(string s) { if (visited.find(s) != visited.end()) return false; if(s == t) return true; visited.insert(s); for (int i = 0; i < n-1; i++) { int u = g[i][0]; int v = g[i][1]; if (s[u] == s[v]) continue; int tmp = s[u]; s[u] = s[v]; if(dfs(s)) return true; s[u] = tmp; tmp = s[v]; s[v] = s[u]; if(dfs(s)) return true;; s[v] = tmp; } return false; } bool solve() { visited.clear(); scanf("%d", &n); scanf("%s\n%", color); s = string(color); scanf("%s\n%", color); t = string(color); for (int i = 0; i < n - 1; i++) { int a, b; scanf("%d %d", &a, &b); a--; b--; g[i][0] = a; g[i][1] = b; } return dfs(s); } int main() { int t; scanf("%d", &t); for (int i = 0; i < t; i++) printf("%s\n", solve() ? "TAK" : "NIE"); } |