Submission #713855

#	Time	Username	Problem	Language	Result	Execution time	Memory
713855		thinknoexit	Mutating DNA (IOI21_dna)	C++17	100 / 100	57 ms	9712 KiB

dna

#include "dna.h"
int dp1[3][100100], dp2[3][100100];
int dp[3][3][100100];
char h[26];
void init(std::string a, std::string b) {
	h[0] = 0;
	h['T' - 'A'] = 1;
	h['C' - 'A'] = 2;
	for (int i = 1;i <= (int)a.size();i++) {
		char c = a[i - 1];
		dp1[0][i] = dp1[0][i - 1] + (c == 'A');
		dp1[1][i] = dp1[1][i - 1] + (c == 'T');
		dp1[2][i] = dp1[2][i - 1] + (c == 'C');
	}
	for (int i = 1;i <= (int)b.size();i++) {
		char c = b[i - 1];
		dp2[0][i] = dp2[0][i - 1] + (c == 'A');
		dp2[1][i] = dp2[1][i - 1] + (c == 'T');
		dp2[2][i] = dp2[2][i - 1] + (c == 'C');
	}
	for (int i = 1;i <= (int)a.size();i++) {
		for (int j = 0;j < 3;j++) {
			for (int k = 0;k < 3;k++) {
				dp[j][k][i] = dp[j][k][i - 1] + (h[a[i - 1] - 'A'] == j && h[b[i - 1] - 'A'] == k);
			}
		}
	}
}

int get_distance(int x, int y) {
	int l = x, r = y;
	r++, l++;
	bool ch = 1;
	for (int k = 0;k < 3;k++) {
		ch &= (dp1[k][r] - dp1[k][l - 1] == dp2[k][r] - dp2[k][l - 1]);
	}
	if (!ch) {
		return -1;
	}
	int now[3][3] = {};
	for (int i = 0;i < 3;i++) {
		for (int j = 0;j < 3;j++) {
			now[i][j] = dp[i][j][r] - dp[i][j][l - 1];
		}
	}
	int cnt = 0;
	for (int i = 0;i < 3;i++) {
		for (int j = i + 1;j < 3;j++) {
			int mn;
			if (now[i][j] > now[j][i]) mn = now[j][i];
			else mn = now[i][j];
			cnt += mn;
			now[i][j] -= mn;
			now[j][i] -= mn;
		}
	}
	int cnt2 = 0;
	for (int i = 0;i < 3;i++) {
		for (int j = 0;j < 3;j++) {
			if (i == j) continue;
			cnt2 += now[i][j];
		}
	}
	return cnt + cnt2 * 2 / 3;
}

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