// 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<bits/stdc++.h>
using namespace std;
#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;
}
const int N = 5010;
int cnt[N];
char a[N], b[N];
string guess(int n, int s) {
vector<pair<int, char> > lst;
for(int j = 0; j < s; j++) {
char c = j + 'a';
string ask;
for(int i = 1; i <= n; i++) ask.push_back(c);
lst.emplace_back(query(ask), c);
}
sort(lst.begin(), lst.end());
int m; char c;
tie(m, c) = lst[0];
for(int i = 1; i <= m; i++) a[i] = c;
lst.erase(lst.begin());
for(auto &it : lst) {
int num; char c;
tie(num, c) = it;
for(int i = 0; i <= m; i++) {
string ask;
for(int j = 1; j <= i; j++) ask.push_back(a[j]);
cnt[i] = 0;
while (num > 0) {
ask.push_back(c);
string tmp;
for(int j = i + 1; j <= m; j++) tmp.push_back(a[j]);
if (query(ask + tmp) > m + cnt[i]) cnt[i]++, num--;
else break;
}
}
int m2 = 0;
for(int i = 0; i <= m; i++) {
if (i) b[++m2] = a[i];
while (cnt[i]--) b[++m2] = c;
}
for(int i = 1; i <= m2; i++) a[i] = b[i];
m = m2;
}
string ret;
for(int i = 1; i <= m; i++) ret.push_back(a[i]);
return ret;
}
int main() {
// ifstream f("password.in");
cin >> n >> s >> password;
// cin.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;
}
Compilation message
/usr/bin/ld: /tmp/ccK5DMJU.o: in function `query(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >)':
grader.cpp:(.text+0x80): multiple definition of `query(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >)'; /tmp/ccTAaTiS.o:password.cpp:(.text+0x690): first defined here
/usr/bin/ld: /tmp/ccK5DMJU.o: in function `main':
grader.cpp:(.text.startup+0x0): multiple definition of `main'; /tmp/ccTAaTiS.o:password.cpp:(.text.startup+0x0): first defined here
collect2: error: ld returned 1 exit status
