Submission #1142530

#	Time	Username	Problem	Language	Result	Execution time	Memory
1142530		vyaduct	Mutating DNA (IOI21_dna)	C++20	100 / 100	20 ms	4880 KiB

dna

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

const int N = 100'001;
int AT[N], TA[N], AC[N], CA[N], CT[N], TC[N];

void init(string a, string b) {
	int n = (int)a.size();
	for (int i=0;i<n;i++){
		AT[i] = (i==0?0:AT[i-1]) + (a[i] == 'A' && b[i] == 'T');
		TA[i] = (i==0?0:TA[i-1]) + (a[i] == 'T' && b[i] == 'A');
		AC[i] = (i==0?0:AC[i-1]) + (a[i] == 'A' && b[i] == 'C');
		CA[i] = (i==0?0:CA[i-1]) + (a[i] == 'C' && b[i] == 'A');
		CT[i] = (i==0?0:CT[i-1]) + (a[i] == 'C' && b[i] == 'T');
		TC[i] = (i==0?0:TC[i-1]) + (a[i] == 'T' && b[i] == 'C');
	}
}

int get_distance(int x, int y) {
	int at = AT[y] - (x==0?0:AT[x-1]);
	int ta = TA[y] - (x==0?0:TA[x-1]);
	int ac = AC[y] - (x==0?0:AC[x-1]);
	int ca = CA[y] - (x==0?0:CA[x-1]);
	int ct = CT[y] - (x==0?0:CT[x-1]);
	int tc = TC[y] - (x==0?0:TC[x-1]);

	int ans = 0;


	int m1=min(at, ta), m2=min(ac,ca), m3=min(tc,ct);
	at -= m1, ta -= m1;
	ac -= m2, ca -= m2;
	tc -= m3, ct -= m3;
	ans += m1 + m2 + m3;
	int fa = at-ta + ac - ca;
	int ft = ta-at + tc - ct;
	int fc = ca-ac + ct - tc;

	if (fa != 0 || ft != 0 || fc != 0) {
		return -1;
	}
	int sum = at + ta + ac + ca + ct + tc;
	return ans + (sum/3)*2;
}

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