Submission #1189598

#	Time	Username	Problem	Language	Result	Execution time	Memory
1189598		Joo	Mutating DNA (IOI21_dna)	C++20	100 / 100	22 ms	6152 KiB

dna

#include "dna.h"
#include <bits/stdc++.h>
using namespace std;

const int C = 3;
const int MXN = 1e5 + 10;

int n;
int qs[MXN][3][3];

inline int parse(char c) {
	if (c == 'A') return 0;
	if (c == 'C') return 1;
	return 2;
}

void init(std::string a, std::string b) {
	n = a.size();
	for (int i = 1; i <= n; i++) {
		for (int j = 0; j < C; j++) {
			for (int k = 0; k < C; k++) {
				qs[i][j][k] += qs[i - 1][j][k];
			}
		}
		int x = parse(a[i - 1]);
		int y = parse(b[i - 1]);
		qs[i][x][y] += 1;
	}
}

int get_distance(int x, int y) {
	x += 1, y += 1;
	int sum[3][3] = {};
	int used[3] = {};
	for (int j = 0; j < C; j++) {
		for (int k = 0; k < C; k++) {
			sum[j][k] = qs[y][j][k] - qs[x - 1][j][k];
		}
	}	

	used[0] = min(sum[0][1], sum[1][0]);
	used[1] = min(sum[0][2], sum[2][0]);
	used[2] = min(sum[1][2], sum[2][1]);

	sum[0][1] -= used[0], sum[1][0] -= used[0];
	sum[0][2] -= used[1], sum[2][0] -= used[1];
	sum[2][1] -= used[2], sum[1][2] -= used[2];

	if (sum[0][1] != sum[1][2] or sum[1][2] != sum[2][0] or sum[1][0] != sum[0][2] or sum[0][2] != sum[2][1]) return -1;
	return max(sum[0][1], sum[1][0]) * 2 + used[0] + used[1] + used[2];
}

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