Submission #438147

#	Time	Username	Problem	Language	Result	Execution time	Memory
438147		josiftepe	Mutating DNA (IOI21_dna)	C++17	56 / 100	51 ms	6316 KiB

dna

#include <iostream>
#include <vector>
#include <algorithm>
#include <cstring>
#include "dna.h"
using namespace std;
const int maxn = 1e5 + 5;
int a_pref_sum[maxn][4];
int b_pref_sum[maxn][4];
int pref_sum[maxn];
string a, b;
vector<int> a_id[4], b_id[4];
int n;
void init(string a, string b) {
    memset(a_pref_sum, 0, sizeof a_pref_sum);
    memset(b_pref_sum, 0, sizeof b_pref_sum);
    
    n = (int) a.size();
    for(int i = 0; i < n; i++) {
        if(a[i] == 'C') a[i] = 'B';
        if(b[i] == 'C') b[i] = 'B';
    }
    for(int i = 0; i < n; i++) {
        if(a[i] == 'T') a[i] = 'C';
        if(b[i] == 'T') b[i] = 'C';
    }
    ::a = a;
    ::b = b;
    int cnt_a[3] = {0, 0, 0};
    int cnt_b[3] = {0, 0, 0};
    int sum = 0;
    for(int i = 0; i < n; i++) {
        int id_a = (int) (a[i] - 'A');
        int id_b = (int) (b[i] - 'A');
        cnt_a[id_a]++;
        cnt_b[id_b]++;
        for(int j = 0; j < 3; j++) {
            a_pref_sum[i][j] = cnt_a[j];
            b_pref_sum[i][j] = cnt_b[j];
        }
        if(a[i] != b[i]) {
            sum++;
        }
        pref_sum[i] = sum;
    }
   
}
int a_query(int &x, int &y, char c) {
    if(x == 0) {
        return a_pref_sum[y][c - 'A'];
    }
    return a_pref_sum[y][c - 'A'] - a_pref_sum[x - 1][c - 'A'];
}
int b_query(int &x, int &y, char c) {
    if(x == 0) {
        return b_pref_sum[y][c - 'A'];
    }
    return b_pref_sum[y][c - 'A'] - b_pref_sum[x - 1][c - 'A'];
}
int get_distance(int x, int y) {
    if(a_query(x, y, 'A') == b_query(x, y, 'A') and a_query(x, y, 'B') == b_query(x, y, 'B') and a_query(x, y, 'C') == b_query(x, y, 'C')) {
        if(x == 0) {
            return (pref_sum[y] + 1) / 2;
        }
        return (pref_sum[y] - pref_sum[x - 1] + 1) / 2;
        }
    
    return -1;
}

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