Submission #437116

#	Time	Username	Problem	Language	Result	Execution time	Memory
437116		MilosMilutinovic	Mutating DNA (IOI21_dna)	C++17	100 / 100	70 ms	6016 KiB

dna

#include <bits/stdc++.h>

using namespace std;

const int N = 1e5 + 5;

int pref[N][3][3];
map<char, int> mp;

void init(string a, string b) {
  mp['A'] = 0;
  mp['C'] = 1;
  mp['T'] = 2;
  int n = (int) a.size();
  for (int i = 0; i < n; i++) {
    for (int j = 0; j < 3; j++) {
      for (int k = 0; k < 3; k++) {
        pref[i + 1][j][k] = pref[i][j][k] + (j == mp[a[i]] && k == mp[b[i]]);
      }
    }
  }
}

int get_distance(int l, int r) {
  vector<vector<int>> tmp(3, vector<int>(3));
  for (int i = 0; i < 3; i++) {
    for (int j = 0; j < 3; j++) {
      tmp[i][j] = pref[r + 1][i][j] - pref[l][i][j];
    }
  }
  if (tmp[0][1] + tmp[0][2] != tmp[1][0] + tmp[2][0]) {
    return -1;
  }
  if (tmp[1][0] + tmp[1][2] != tmp[0][1] + tmp[2][1]) {
    return -1;
  }
  int ans = 0;
  for (int i = 0; i < 3; i++) {
    for (int j = i + 1; j < 3; j++) {
      int mn = min(tmp[i][j], tmp[j][i]);
      tmp[i][j] -= mn;
      tmp[j][i] -= mn;
      ans += mn;
    }
  }
  int add = 1e9;
  for (int i = 0; i < 3; i++) {
    for (int j = i + 1; j < 3; j++) {
      add = min(add, max(tmp[i][j], tmp[j][i]));
    }
  }
  return ans + add * 2;
}

• Subtask 1: 21 / 21
• Subtask 2: 22 / 22
• Subtask 3: 13 / 13
• Subtask 4: 28 / 28
• Subtask 5: 16 / 16