Submission #657905

#	Time	Username	Problem	Language	Result	Execution time	Memory
657905		benjaminkleyn	Mutating DNA (IOI21_dna)	C++17	100 / 100	48 ms	6168 KiB

dna

#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2,fma,bmi,bmi2")
#include <bits/stdc++.h>
using namespace std;

int n, pref[3][3][100001], cnt[3][3];
void init(string A, string B)
{
    n = A.size();
    for (int i = 0, a, b; i < n; i++)
    {
        for (a = 0; a < 3; a++)
            for (b = 0; b < 3; b++)
                pref[a][b][i + 1] = pref[a][b][i];
        a = (A[i] == 'C') + 2 * (A[i] == 'T');
        b = (B[i] == 'C') + 2 * (B[i] == 'T');
        pref[a][b][i + 1]++;
    }
}

int get_distance(int x, int y)
{
    for (int a = 0; a < 3; a++)
        for (int b = 0; b < 3; b++)
            cnt[a][b] = pref[a][b][y + 1] - pref[a][b][x];
    for (int i = 0; i < 3; i++)
        if (cnt[i][0] + cnt[i][1] + cnt[i][2] != cnt[0][i] + cnt[1][i] + cnt[2][i])
            return -1;
    return 2 * max(cnt[0][1], cnt[1][0]) - min(cnt[0][1], cnt[1][0]) + min(cnt[1][2], cnt[2][1]) + min(cnt[2][0], cnt[0][2]);
}

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