Submission #442803

#	Time	Username	Problem	Language	Result	Execution time	Memory
442803		alan8585	Mutating DNA (IOI21_dna)	C++17	100 / 100	87 ms	6016 KiB

dna

#include "dna.h"
#include <vector>
using namespace std;

int n, pre[100100][3][3];

int tran(char c) {
	if(c == 'A') return 0;
	if(c == '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 = tran(a[i]), y = tran(b[i]);
		for(int j = 0; j < 3; j++) {
			for(int k = 0; k < 3; k++) {
				pre[i + 1][j][k] = pre[i][j][k] + (j == x && k == y);
			}
		}
	}
}

int get_distance(int x, int y) {
	x++, y++;
	vector<int> acnt(3), bcnt(3);
	vector<vector<int>> m(3, vector<int>(3));
	for(int i = 0; i < 3; i++) {
		for(int j = 0; j < 3; j++) {
			acnt[i] += pre[y][i][j] - pre[x - 1][i][j];
			bcnt[j] += pre[y][i][j] - pre[x - 1][i][j];
			m[i][j] = pre[y][i][j] - pre[x - 1][i][j];
		}
	}
	for(int i = 0; i < 3; i++)
		if(acnt[i] != bcnt[i])
			return -1;
	int ans = 0;
	for(int i = 0; i < 3; i++) {
		for(int j = i + 1; j < 3; j++) {
			int now = min(m[i][j], m[j][i]);
			m[i][j] -= now;
			m[j][i] -= now;
			ans += now;
		}
	}
	if(m[0][1]) {
		if(m[0][1] != m[1][2] || m[0][1] != m[2][0])
			while(1);
		if(m[0][2] || m[1][0] || m[2][1])
			while(1);
		ans += m[0][1] * 2;
	} else if(m[0][2]) {
		if(m[0][2] != m[1][0] || m[0][2] != m[2][1])
			while(1);
		if(m[0][1] || m[1][2] || m[2][0])
			while(1);
		ans += m[0][2] * 2;
	}
	return ans;
}

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