Submission #438203

#	Time	Username	Problem	Language	Result	Execution time	Memory
438203		SHZhang	Mutating DNA (IOI21_dna)	C++17	100 / 100	50 ms	6596 KiB

dna

#include "dna.h"
#include <algorithm>

using namespace std;

int n;

char a[100005], b[100005];
int acnt[100005], tcnt[100005], ccnt[100005];
int at[100005], ta[100005], ac[100005],
    ca[100005], ct[100005], tc[100005];

void init(std::string x, std::string y) {
    n = (int)x.size();
    for (int i = 0; i < n; i++) a[i+1] = x[i];
    for (int i = 0; i < n; i++) b[i+1] = y[i];
    for (int i = 1; i <= n; i++) {
        acnt[i] = acnt[i-1] + (a[i] == 'A' ? 1 : 0) - (b[i] == 'A' ? 1 : 0);
        tcnt[i] = tcnt[i-1] + (a[i] == 'T' ? 1 : 0) - (b[i] == 'T' ? 1 : 0);
        ccnt[i] = ccnt[i-1] + (a[i] == 'C' ? 1 : 0) - (b[i] == 'C' ? 1 : 0);
        at[i] = at[i-1] + (a[i] == 'A' && b[i] == 'T' ? 1 : 0);
        ta[i] = ta[i-1] + (a[i] == 'T' && b[i] == 'A' ? 1 : 0);
        ac[i] = ac[i-1] + (a[i] == 'A' && b[i] == 'C' ? 1 : 0);
        ca[i] = ca[i-1] + (a[i] == 'C' && b[i] == 'A' ? 1 : 0);
        ct[i] = ct[i-1] + (a[i] == 'C' && b[i] == 'T' ? 1 : 0);
        tc[i] = tc[i-1] + (a[i] == 'T' && b[i] == 'C' ? 1 : 0);
    }
}

int get_distance(int x, int y) {
	x++; y++;
    int adiff = acnt[y] - acnt[x-1];
    int tdiff = tcnt[y] - tcnt[x-1];
    int cdiff = ccnt[y] - ccnt[x-1];
    if (adiff != 0 || tdiff != 0 || cdiff != 0) return -1;
    int n_at = at[y] - at[x-1];
    int n_ta = ta[y] - ta[x-1];
    int n_ac = ac[y] - ac[x-1];
    int n_ca = ca[y] - ca[x-1];
    int n_ct = ct[y] - ct[x-1];
    int n_tc = tc[y] - tc[x-1];
    int min1 = min(n_at, n_ta);
    int min2 = min(n_ac, n_ca);
    int min3 = min(n_ct, n_tc);
    n_at -= min1; n_ta -= min1;
    n_ac -= min2; n_ca -= min2;
    n_ct -= min3; n_tc -= min3;
    return min1 + min2 + min3 + 2 * max(n_at, n_ta);
}

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