Submission #829866

#	Time	Username	Problem	Language	Result	Execution time	Memory
829866		Sohsoh84	Mutating DNA (IOI21_dna)	C++17	100 / 100	31 ms	8628 KiB

dna

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

using namespace std;

#define sep		' '
#define debug(x)	cerr << #x << ": " << x << endl;

const int MAXN = 1e6 + 10;

int n, ps[MAXN], c1[MAXN], c2[MAXN], f[MAXN][3][3];

inline int r(char x) {
	if (x == 'A') return 0;
	if (x == 'T') return 1;
	return 2;
}

void init(string a, string b) {
	n = a.size();
	a = '#' + a;
	b = '#' + b;
	
	for (int i = 1; i <= n; i++) {
		ps[i] = ps[i - 1] + (a[i] != b[i]);
		c1[i] = c1[i - 1] + (a[i] == 'A') - (b[i] == 'A');
		c2[i] = c2[i - 1] + (a[i] == 'T') - (b[i] == 'T');
		
		for (int a = 0; a < 3; a++)
			for (int b = 0; b < 3; b++)
				f[i][a][b] = f[i - 1][a][b];

		f[i][r(a[i])][r(b[i])]++;
	}
}

int get_distance(int x, int y) {
	x++;
	y++;

	if (c1[y] - c1[x - 1] || c2[y] - c2[x - 1]) return -1;

	int ans = 0;
	int ms = ps[y] - ps[x - 1];

	for (int i = 0; i < 3; i++) {
		for (int j = i + 1; j < 3; j++) {
			int c = min(f[y][i][j] - f[x - 1][i][j], f[y][j][i] - f[x - 1][j][i]);
			ms -= 2 * c;
			ans += c;
		}
	}

	ans += ms * 2 / 3;
	return ans;
}

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