Submission #1237182

#	Time	Username	Problem	Language	Result	Execution time	Memory
1237182		SalihSahin	Mutating DNA (IOI21_dna)	C++20	100 / 100	33 ms	9800 KiB

dna

#include "bits/stdc++.h"
#include "dna.h"
using namespace std;

vector<vector<int> > pre; 

void init(string a, string b){
   int n = a.size();
   pre.resize(n+1);
   for(int i = 0; i <= n; i++){
      pre[i].resize(9);
   }
   for(int i = 0; i < n; i++){
      int val = 0;
      if(a[i] == 'T') val += 3;
      else if(a[i] == 'C') val += 6;
      if(b[i] == 'T') val += 1;
      else if(b[i] == 'C') val += 2;
      for(int j = 0; j < 9; j++){
         pre[i+1][j] = pre[i][j];
      }
      pre[i+1][val]++;
   }
}

int get_distance(int x, int y){
   vector<int> cnt(9);
   for(int i = 0; i < 9; i++){
      cnt[i] = pre[y+1][i] - pre[x][i];
   }

   vector<int> tota(3), totb(3);
   for(int i = 0; i < 9; i++){
      tota[i/3] += cnt[i];
      totb[i%3] += cnt[i];
   }

   if(tota[0] != totb[0] || tota[1] != totb[1] || tota[2] != totb[2]){
      return -1;
   }

   int ans = 0;
   cnt[0] = cnt[4] = cnt[8] = 0; // AA, TT, CC

   int c1 = min(cnt[1], cnt[3]); // AT, TA
   ans += c1;
   cnt[1] -= c1;
   cnt[3] -= c1;

   int c2 = min(cnt[2], cnt[6]); // AC, CA
   ans += c2;
   cnt[2] -= c2;
   cnt[6] -= c2;

   int c3 = min(cnt[5], cnt[7]); // TC, CT
   ans += c3;
   cnt[5] -= c3;
   cnt[7] -= c3;

   int rem = 0;
   for(int i = 0; i < 9; i++){
      rem += cnt[i];
   }
   int add = (rem / 3) * 2;
   ans += add;

   return ans;
}

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