Submission #1214264

#	Time	Username	Problem	Language	Result	Execution time	Memory
1214264		trimkus	Mutating DNA (IOI21_dna)	C++20	21 / 100	28 ms	2376 KiB

dna

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


map<char, int> mp;
string a, b;
void init(std::string _a, std::string _b) {
	a = _a;
	b = _b;
	mp['A'] = 0;
	mp['T'] = 1;
	mp['C'] = 2;
}
// 1, 2, 4
// 8, 16, 32
int get_distance(int x, int y) {
	vector<vector<int>> d1(3), d2(3);
	vector<int> cnt(60);
	vector<int> bal(3);
	int res = 0;
	int left = y - x + 1;
	for (int i = x; i <= y; ++i) {
		int ai = mp[a[i]];
		int bi = mp[b[i]];
		if (ai == bi) {
			left -= 1;
			continue;
		}
		d1[mp[a[i]]].push_back(i);
		d2[mp[b[i]]].push_back(i);
		cnt[(1 << ai) + (1 << (bi + 3))] += 1;
		bal[ai] += 1;
		bal[bi] -= 1;
	}
	for (int mask1 : {1, 2, 4}) {
		for (int mask2 : {8, 16, 32}) {
			int rev1 = (1 << (mask1 + 3));
			int rev2 = mask2 >> 3;
			int take = min(cnt[mask1 + mask2], cnt[rev1 + rev2]);
			res += take;
			cnt[mask1 + mask2] -= take;
			cnt[rev1 + rev2] -= take;
			left -= take;
		}
	}
	for (auto& i : bal) {
		if (i != 0) return -1;
	}
	// cerr << "[" << a.substr(x, y - x + 1) << " , " << b.substr(x, y - x + 1) << "] = " << res << "\n";
	// assert(res % 2 == 0);
	return res + max(0, left - 1);
}

• Subtask 1: 21 / 21
• Subtask 2: 0 / 22
• Subtask 3: 0 / 13
• Subtask 4: 0 / 28
• Subtask 5: 0 / 16