Submission #569058

#	Time	Username	Problem	Language	Result	Execution time	Memory
569058		MEGalodon	Mutating DNA (IOI21_dna)	C++17	100 / 100	44 ms	10888 KiB

dna

#include "dna.h"
using namespace std;
typedef long long ll;
const int N = 1e5+23;

int n;
int a[N],b[N];
int pref[N][4][4];

void init(std::string s, std::string t) {
    n = s.size();
    for(int i = 1; i <= n; i++){
        if(s[i-1] == 'A') a[i] = 1;
        else if(s[i-1] == 'C') a[i] = 2;
        else a[i] = 3;
        if(t[i-1] == 'A') b[i] = 1;
        else if(t[i-1] == 'C') b[i] = 2;
        else b[i] = 3;
    }

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

int sta[4][4];
int get_distance(int x, int y) {
    x++;
    y++;
    for(int i = 1; i <= 3; i++){
        for(int j = 1; j <= 3; j++){
            sta[i][j] = pref[y][i][j]-pref[x-1][i][j];
        }
    }

    for(int i = 1; i <= 3; i++){
        int s1 = 0;
        for(int j = 1; j <= 3; j++) s1 += sta[i][j];
        int s2 = 0;
        for(int j = 1; j <= 3; j++) s2 += sta[j][i];
        if(s1 != s2){
            return -1;
        }
    }

    int v1 = min(sta[1][2],sta[2][1]);
    int v2 = min(sta[2][3],sta[3][2]);
    int v3 = min(sta[1][3],sta[3][1]);
    int dod = 2*abs(sta[1][2]-sta[2][1]);

    return v1+v2+v3+dod;
}

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