Submission #480387

#	Time	Username	Problem	Language	Result	Execution time	Memory
480387		inventiontime	Mutating DNA (IOI21_dna)	C++17	100 / 100	55 ms	10108 KiB

dna

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

#define MAXN 100005

int n;
int pairs[3][3][MAXN];
int of[2][3][MAXN];
int diff[MAXN];

map<char, int> code = {{'A', 0}, {'T', 1}, {'C', 2}};

void init(std::string a, std::string b) {
	n = a.length();

	diff[0] = 0;
	for(int i = 0; i < 3; i++) {
		for(int j = 0; j < 2; j++) of[j][i][0] = 0;
		for(int j = 0; j < 3; j++) pairs[j][i][0] = 0;
	}

	for(int i = 1; i <= n; i++) {
		for(int j = 0; j < 2; j++) for(int k = 0; k < 3; k++) of[j][k][i] = of[j][k][i-1];
		for(int j = 0; j < 3; j++) for(int k = 0; k < 3; k++) pairs[j][k][i] = pairs[j][k][i-1];
		diff[i] = diff[i-1];
		
		of[0][code[a[i-1]]][i]++;
		of[1][code[b[i-1]]][i]++;

		if(a[i-1] != b[i-1]) {
			diff[i]++;
			pairs[code[a[i-1]]][code[b[i-1]]][i]++;
		}
	}
}

int swaps(int x, int y, int n1, int n2) {
	return min(pairs[n1][n2][y] - pairs[n1][n2][x], pairs[n2][n1][y] - pairs[n2][n1][x]);
}

int get_distance(int x, int y) {
	x--;
	x++;
	y++;
	if(of[0][0][y] - of[0][0][x] == of[1][0][y] - of[1][0][x]
	&& of[0][1][y] - of[0][1][x] == of[1][1][y] - of[1][1][x]
	&& of[0][2][y] - of[0][2][x] == of[1][2][y] - of[1][2][x]) {
		int one_swap = swaps(x, y, 0, 1) + swaps(x, y, 1, 2) + swaps(x, y, 2, 0);
		float two_swap = (float) (diff[y] - diff[x] - 2*one_swap)/3;
		return ((diff[y] - diff[x]) - 2*one_swap)*2/3 + one_swap;
	}
		
	return -1;
}

Compilation message (stderr)

dna.cpp: In function 'int get_distance(int, int)':
dna.cpp:50:9: warning: unused variable 'two_swap' [-Wunused-variable]
   50 |   float two_swap = (float) (diff[y] - diff[x] - 2*one_swap)/3;
      |         ^~~~~~~~

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