Submission #464224

#	Time	Username	Problem	Language	Result	Execution time	Memory
464224		ljuba	Mutating DNA (IOI21_dna)	C++17	100 / 100	128 ms	34684 KiB

dna

#include "dna.h"
#include <bits/stdc++.h>

using namespace std;

vector<vector<int>> pref, pref2;
map<char, int> mp;
int n;

vector<vector<vector<int>>> cnt;

void init(std::string _a, std::string _b) {
    mp['A'] = 0;
    mp['C'] = 1;
    mp['T'] = 2;
    n = (int)_a.size();
    vector<int> a(n), b(n);
    for(int i = 0; i < n; ++i) {
        a[i] = mp[_a[i]];
    }
    for(int i = 0; i < n; ++i) {
        b[i] = mp[_b[i]];
    }

    pref.assign(n, vector<int>(3, 0));
    pref2.assign(n, vector<int>(3, 0));

    pref[0][a[0]] = 1;

    for(int i = 1; i < n; ++i) {
        for(int j = 0; j < 3; ++j) {
            pref[i][j] = pref[i-1][j];
        }
        ++pref[i][a[i]];
    }

    pref2[0][b[0]] = 1;
    for(int i = 1; i < n; ++i) {
        for(int j = 0; j < 3; ++j) {
            pref2[i][j] = pref2[i-1][j];
        }
        ++pref2[i][b[i]];
    }

    cnt.assign(n, vector<vector<int>>(3, vector<int>(3, 0)));
    cnt[0][a[0]][b[0]] = 1;

    for(int i = 1; i < n; ++i) {
        for(int j = 0; j < 3; ++j) {
            for(int k = 0; k < 3; ++k) {
                cnt[i][j][k] = cnt[i-1][j][k];
            }
        }
        ++cnt[i][a[i]][b[i]];
    }
}

int get_distance(int x, int y) {
    for(int j = 0; j < 3; ++j) {
        int s1 = pref[y][j];
        if(x-1 >= 0)
            s1 -= pref[x-1][j];
        int s2 = pref2[y][j];
        if(x-1 >= 0)
            s2 -= pref2[x-1][j];

        if(s1 != s2) {
            return -1;
        }
    }
    int ans = 0;
    int vel = y - x + 1;
    for(int j = 0; j < 3; ++j) {
        int s1 = cnt[y][j][j];
        if(x-1 >= 0)
            s1 -= cnt[x-1][j][j];
        vel -= s1;
    }

    for(int j = 0; j < 3; ++j) {
        for(int k = j+1; k < 3; ++k) {
            int ima1 = cnt[y][j][k];
            if(x - 1 >= 0)
                ima1 -= cnt[x-1][j][k];
            int ima2 = cnt[y][k][j];
            if(x - 1 >= 0)
                ima2 -= cnt[x-1][k][j];

            ans += min(ima1, ima2);
            vel -= 2*min(ima1, ima2);
        }
    }

    //konacno ce izgledati oblika
    //CCAATT
    //TTCCAA
    //ovde treba 4 poteza

    ans += (vel / 3) * 2;

    return ans;
}

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