Submission #444862

#	Time	Username	Problem	Language	Result	Execution time	Memory
444862		apostoldaniel854	Mutating DNA (IOI21_dna)	C++17	100 / 100	57 ms	7396 KiB

dna

#include "dna.h"
#include <map>
#include <vector>
#include <bits/stdc++.h>
using ll = long long;
#define dbg(x) std::cerr << #x << " " << x << "\n"

const int MAX_N = 1e5;
int sum[MAX_N][3][3];

void init(std::string a, std::string b) {
    std::map <char, int> mp;
    mp['A'] = 0, mp['C'] = 1, mp['T'] = 2;
    int n = a.size ();
    for (int i = 0; i < n; i++) {
        if (i > 0) {
            for (int j = 0; j < 3; j++)
                for (int k = 0; k < 3; k++)
                    sum[i][j][k] += sum[i - 1][j][k];
        }
        sum[i][mp[a[i]]][mp[b[i]]]++;
    }
}

int cnt[3][3];
int get_distance(int x, int y) {
    std::vector <int> freqA (3, 0), freqB (3, 0);
    for (int i = 0; i < 3; i++) {
        for (int j = 0; j < 3; j++) {
            cnt[i][j] = sum[y][i][j];
            if (x > 0) {
                cnt[i][j] -= sum[x - 1][i][j];
            }
   //         dbg (i); dbg (j); dbg (cnt[i][j]);
            freqA[i] += cnt[i][j];
            freqB[j] += cnt[i][j];
        }
    }
    for (int i = 0; i < 3; i++)
        if (freqA[i] != freqB[i])
            return -1;
    int ans = 0;
    for (int i = 0; i < 3; i++) {
        for (int j = i + 1; j < 3; j++) {
            int sub = std::min (cnt[i][j], cnt[j][i]);
            ans += sub;
            cnt[i][j] -= sub;
            cnt[j][i] -= sub;
        }
    }
    int to_add = 0;
    for (int i = 0; i < 3; i++) {
        for (int j = 0; j < 3; j++) {
            if (i != j && cnt[i][j]) {
                to_add = cnt[i][j];
            }
        }
    }
    ans += 2 * to_add;
	return ans;
}

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