Submission #251466

#	Time	Username	Problem	Language	Result	Execution time	Memory
251466		Bruteforceman	Trobojnica (COCI19_trobojnica)	C++11	110 / 110	197 ms	16248 KiB

trobojnica

#include <bits/stdc++.h>
using namespace std;
const int maxn = 2e5 + 10;
#define endl '\n'
int suc[maxn];
int pre[maxn];
int succol[maxn], precol[maxn];
char a[maxn];
int main() {
  int n;
  scanf("%d", &n);
  scanf("%s", a);
  int freq[] = {0, 0, 0, 0};
  set <int> s[4][4];
  for(int i = 0; i < n; i++) {
    pre[i] = (n + i - 1) % n;
    suc[i] = (i + 1) % n;
    freq[a[i] - '0'] += 1;
    precol[i] = a[pre[i]] - '0';
    succol[i] = a[i] - '0';
    s[precol[i]][succol[i]].insert(i);
  }
  if(freq[1] == n || freq[2] == n || freq[3] == n) {
    puts("NE");
    exit(0);
  }
  if(abs(freq[1] - freq[2]) % 2 == 1 || abs(freq[2] - freq[3]) % 2 == 1) {
    puts("NE");
    exit(0);
  }
  puts("DA");
  int cur = 0;
  for(int i = 0; i < n - 3; i++) {
    int occur = max({freq[1], freq[2], freq[3]});
    int col;
    for(col = 1; col <= 3; col++) {
      if(freq[col] == occur) break;
    }
    bool done = false;
    for(int x = 1; x <= 3; x++) {
      for(int y = 1; y <= 3; y++) {
        if(s[x][y].empty()) continue;
        if(x == y || (x != col && y != col)) continue;
        if(done) continue;
        int cur = *s[x][y].begin();
        s[x][y].erase(cur);
        int p = pre[cur];
        int q = suc[cur];
        int inv = 6 - x - y;
        freq[x] -= 1;
        freq[y] -= 1;
        freq[inv] += 1;
        printf("%d %d %d\n", p + 1, q + 1, inv);
        s[precol[p]][succol[p]].erase(p);
        s[precol[q]][succol[q]].erase(q);
        pre[suc[cur]] = pre[cur]; precol[suc[cur]] = inv;
        suc[pre[cur]] = suc[cur]; succol[pre[cur]] = inv;
        s[precol[p]][succol[p]].insert(p);
        s[precol[q]][succol[q]].insert(q);
        done = true;
      }
    }
  }
  return 0;
}

Compilation message (stderr)

trobojnica.cpp: In function 'int main()':
trobojnica.cpp:32:7: warning: unused variable 'cur' [-Wunused-variable]
   int cur = 0;
       ^~~
trobojnica.cpp:11:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d", &n);
   ~~~~~^~~~~~~~~~
trobojnica.cpp:12:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%s", a);
   ~~~~~^~~~~~~~~

• Subtask 1: 20 / 20
• Subtask 2: 40 / 40
• Subtask 3: 50 / 50