Submission #1271303

#	Time	Username	Problem	Language	Result	Execution time	Memory
1271303		nerrrmin	Mutating DNA (IOI21_dna)	C++20	71 / 100	1593 ms	5704 KiB

dna

#include "dna.h"
#define pb push_back
#include <bits/stdc++.h>
using namespace std;
const int maxn = 2e5 + 10;
int n, prefa[maxn][3], prefb[maxn][3];
int is_cool[maxn], cool[maxn];
vector < pair < char, char > > g;
string aa, bb;
void init(std::string a, std::string b)
{
    n = a.size();
    aa = a;
    bb = b;
    for (int i = 0; i < a.size(); ++ i)
    {
        for (int j = 0; j < 3 && i; ++ j)
            prefa[i][j] = prefa[i-1][j];
        if(a[i] == 'A')prefa[i][0] ++;
        else if(a[i] == 'T')prefa[i][1] ++;
        else prefa[i][2] ++;
    }
    for (int i = 0; i < b.size(); ++ i)
    {
        for (int j = 0; j < 3 && i; ++ j)
            prefb[i][j] = prefb[i-1][j];
        if(b[i] == 'A')prefb[i][0] ++;
        else if(b[i] == 'T')prefb[i][1] ++;
        else prefb[i][2] ++;
    }
    for (int i = 0; i < n; ++ i)
    {
        if(i)cool[i] = cool[i-1];
        if(a[i] == b[i])is_cool[i] = 1;
        cool[i] += is_cool[i];
    }
    g.pb(make_pair('A', 'C'));
     g.pb(make_pair('A', 'T'));
      g.pb(make_pair('C', 'T'));
}
int geta(int lt, int rt, int t)
{
    int cnt = prefa[rt][t];
    if(lt > 0)cnt -= prefa[lt-1][t];
    return cnt;
}
int getb(int lt, int rt, int t)
{
    int cnt = prefb[rt][t];
    if(lt > 0)cnt -= prefb[lt-1][t];
    return cnt;
}
map < pair < char, char >, int > mp;
int get_distance(int x, int y)
{
    for (int j = 0; j < 3; ++ j)
    {
        if(geta(x, y, j) != getb(x, y, j))return -1;
    }
    mp.clear();
    int ok = cool[y];
    if(x)ok -= cool[x-1];
    for (int i = x; i <= y; ++ i)
    {
        if(aa[i] != bb[i])
        {
            mp[make_pair(aa[i], bb[i])] ++;
        }
    }
    int lft = y - x + 1 - ok;
    int dvoiki = 0;
    for (auto &[f, s]: g)
    {
        int br = mp[{f, s}];
        int br_rev = mp[{s, f}];
        dvoiki += min(br, br_rev) ;
    }
   int real_left = lft - dvoiki * 2;
	return max(0, max(0, real_left/3 * 2) + dvoiki);
}

• Subtask 1: 21 / 21
• Subtask 2: 22 / 22
• Subtask 3: 0 / 13
• Subtask 4: 28 / 28
• Subtask 5: 0 / 16