# | Submission time | Handle | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
918609 | 2024-01-30T07:31:04 Z | AtabayRajabli | Password (RMI18_password) | C++17 | 0 ms | 0 KB |
// Sample grader for contestants' use. // // Usage: place your input data in the file password.in in the format // // line 1: N S // line 2: hidden_password // // Then compile this grader together with your implementation. // Run the binary to see your guessing strategy at work! // Set DEBUG to 1 to print all queries. #include <fstream> #include <iostream> #include <sstream> #include <string> #include <stdlib.h> #include <assert.h> using namespace std; #define DEBUG 0 #define MAX_QUERIES 50000 #define MAX_N 5000 #define MAX_SIGMA 26 static string password; static int n, s, numQueries; static stringstream msg; static void end(int success) { cout << (success ? "SUCCESS! " : "ERROR: ") << msg.str() << endl; exit(0); } int query(string q) { if (++numQueries > MAX_QUERIES) { msg << "Could not guess the password with " << MAX_QUERIES << " questions."; end(0); } int len = q.size(); // validation if (len < 1 || len > n) { msg << "Query '" << q << "' should have length between 1 and " << n << " characters."; end(0); } for (int i = 0; i < len; i++) { if (q[i] < 'a' || q[i] >= 'a' + s) { msg << "Illegal character '" << q[i] << "' found."; end(0); } } // while possible, advance one character in q and find its next // occurrence in password int i = 0, j = 0, plen = password.size(); while (i < plen && j < len) { while ((i < plen) && (password[i] != q[j])) { i++; } if (i < plen) { /* found a match */ i++; j++; } } if (DEBUG) { cout << "Question #" << numQueries << " [" << q << "] answer " << j << endl; } return j; } string guess(int n, int s) { int comb[26][26] = {0}; int freq[26] = {0}; for(int i = 0; i < 26; i++) { int l = 0, r = n; while(l <= r) { int mid = (l + r) / 2; string x = ""; for(int j = 0; j < mid; j++)x += (char(i + 'a')); if(query(x) == x.size())l = mid + 1; else r = mid - 1; } freq[i] = l - 1; } string ans = ""; for(int i = 0; i < s; i++) { for(int j = 0; j < s; j++) { string x = ""; x.push_back(char(i +'a')); int cnt = freq[j]; while(cnt--)x.push_back(char(j + 'a')); comb[i][j] = x.size(); } } for(int ind = 0; ind < n; ind++) { for(int i = 0; i < 26; i++) { bool check = 1; for(int j = 0; j < 26; j++) { if(comb[i][j] != freq[j] + 1) { check = 0; break; } } if(check) { ans += char(i + 'a'); freq[i]--; break; } } } return ans; } int main() { ifstream f("password.in"); f >> n >> s >> password; f.close(); assert(n && s && !password.empty()); string answer = guess(n, s); if (DEBUG) { cout << "Your answer: [" << answer << "]\n"; } if (answer.compare(password)) { msg << "Your answer was [" << answer << "] which does not match the password [" << password << "]."; end(0); } else { msg << "You guessed the password with " << numQueries << " queries."; end(1); } return 0; }