Submission #1108453

#	Time	Username	Problem	Language	Result	Execution time	Memory
1108453		huyngo	Mutating DNA (IOI21_dna)	C++17	100 / 100	42 ms	7456 KiB

dna

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

const int mxN = 1e5 + 5;
int n;
int c[3][3][mxN];

int encode(char ch) {
	if (ch == 'A') return 0;
	if (ch == 'T') return 1;
	return 2;
}

void init(std::string a, std::string b) {
	n = a.size();
	for (int i = 0; i < n; ++i) {
		int x = encode(a[i]);
		int y = encode(b[i]);
		c[x][y][i + 1]++;
	}
	for (int i = 1; i <= n; ++i) {
		for (int x = 0; x < 3; ++x)
			for (int y = 0; y < 3; ++y)
				c[x][y][i] += c[x][y][i - 1];
	}
}

int get_distance(int l, int r) {
	++r;
	int res = -1;
	vector<vector<int>> f(3, vector<int>(3));
	for (int i = 0; i < 3; ++i)
		for (int j = 0; j < 3; ++j) {
			f[i][j] = c[i][j][r] - c[i][j][l];
		}
	int x = f[0][1] - f[1][0];
	int y = f[0][2] - f[2][0];
	int z = f[1][2] - f[2][1];
	if ((x == -y && -y == z) || (-x == y && y == -z)) {
		res = min(f[0][1], f[1][0]) + min(f[0][2], f[2][0]) + min(f[1][2], f[2][1]);
		x = abs(x);
		res += x * 2;
	}
	return res;
}

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