Submission #1364284

#	Time	Username	Problem	Language	Result	Execution time	Memory
1364284		SmuggingSpun	Gingerbread (BOI25_gcd)	C++20	100 / 100	52 ms	4284 KiB

Main

#include<bits/stdc++.h>
#define taskname "C"
using namespace std;
const int lim = 1e6 + 5;
int n, g = 0, a[lim];
bool backtrack(int p, int cnt){
  if(p == n){
    for(int i = g = 0; i < n; i++){
      g = __gcd(g, a[i]);
    }
    return g == 1;
  }
  for(int i = 0; i <= cnt; i++){
    a[p] += i;
    if(backtrack(p + 1, cnt - i)){
      return true;
    }
    a[p] -= i;
  }
  return false;
}
int main(){
	ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
	if(fopen(taskname".inp", "r")){
		freopen(taskname".inp", "r", stdin);
	}
  cin >> n;
  for(int i = 0; i < n; g = __gcd(g, a[i++])){
    cin >> a[i];
  }
  if(g == 1){
    return cout << 0, 0;
  }
  if(n > 15){
    return cout << 1, 0;
  }
  for(int i = 1; true; i++){
    if(backtrack(0, i)){
      return cout << i, 0;
    }
  }
}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:25:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   25 |                 freopen(taskname".inp", "r", stdin);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 0
• Subtask 2: 17 / 17
• Subtask 3: 34 / 34
• Subtask 4: 11 / 11
• Subtask 5: 38 / 38