Submission #982486

#	Time	Username	Problem	Language	Result	Execution time	Memory
982486		faqinyeager	Mutating DNA (IOI21_dna)	C++17	100 / 100	38 ms	9680 KiB

dna

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

int n;
int asum[100050][3], bsum[100050][3];
int cnt[100050][3][3];

void init(std::string a, std::string b){
	n = (int)a.size();
	for(int i = 0; i < n; i ++){
		if(a[i] == 'A') asum[i + 1][0] ++;
		else if(a[i] == 'C') asum[i + 1][1] ++;
		else asum[i + 1][2] ++;
		
		if(b[i] == 'A') bsum[i + 1][0] ++;
		else if(b[i] == 'C') bsum[i + 1][1] ++;
		else bsum[i + 1][2] ++;

		int ai = 2, bi = 2;

		if(a[i] == 'A') ai = 0;
		else if(a[i] == 'C') ai = 1;
		if(b[i] == 'A') bi = 0;
		else if(b[i] == 'C') bi = 1;

		cnt[i + 1][ai][bi] = 1;
	}
	for(int i = 2; i <= n; i ++){
		for(int j = 0; j < 3; j ++){
			asum[i][j] += asum[i - 1][j];
			bsum[i][j] += bsum[i - 1][j];
		}

		for(int j = 0; j < 3; j ++){
			for(int jj = 0; jj < 3; jj ++){
				cnt[i][j][jj] += cnt[i - 1][j][jj];
			}
		}
	}
}

int get_distance(int x, int y){
	x++, y++;
	for(int j = 0; j < 3; j ++){
		if(asum[y][j] - asum[x - 1][j] != bsum[y][j] - bsum[x - 1][j]){
			return -1;
		}
	}
	int c[3][3] = {{0}};
	for(int j = 0; j < 3; j ++){
		for(int jj = 0; jj < 3; jj ++){
			c[j][jj] = cnt[y][j][jj] - cnt[x - 1][j][jj];
		}
	}
	int tmp = min(c[0][1], c[1][0]), ans = 0;
	c[0][1] -= tmp, c[1][0] -= tmp, ans += tmp;
	tmp = min(c[0][2], c[2][0]);
	c[0][2] -= tmp, c[2][0] -= tmp, ans += tmp;
	tmp = min(c[1][2], c[2][1]);
	c[1][2] -= tmp, c[2][1] -= tmp, ans += tmp;

	ans += 2 * (c[0][1] + c[1][0]);
	return ans;
}
// aaaacccctt
// ccccaattaa

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