Submission #437110

#	Time	Username	Problem	Language	Result	Execution time	Memory
437110		dqhungdl	Mutating DNA (IOI21_dna)	C++17	100 / 100	50 ms	6064 KiB

dna

#include "dna.h"

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

int n,S[100005][3][3];

int getId(char c) {
	if(c=='A')
		return 0;
	if(c=='C')
		return 1;
	return 2;
}

void init(std::string a, std::string b) {
	n=a.size();
	for(int i=0;i<n;i++) {
		if(i>0)
			for(int t1=0;t1<3;t1++)
				for(int t2=0;t2<3;t2++)
					S[i][t1][t2]=S[i-1][t1][t2];
		S[i][getId(a[i])][getId(b[i])]++;
	}
}

int get_distance(int x, int y) {
	int C[3][3];
	for(int t1=0;t1<3;t1++)
		for(int t2=0;t2<3;t2++)
			C[t1][t2]=S[y][t1][t2]-(x==0?0:S[x-1][t1][t2]);
	if(C[0][1]+C[0][2]!=C[1][0]+C[2][0]||C[1][0]+C[1][2]!=C[0][1]+C[2][1])
		return -1;
	int s1=0,s2=1e9;
	for(int t1=0;t1<3;t1++)
		for(int t2=t1+1;t2<3;t2++) {
			int tmp=min(C[t1][t2],C[t2][t1]);
			C[t1][t2]-=tmp;
			C[t2][t1]-=tmp;
			s1+=tmp;
		}
	for(int t1=0;t1<3;t1++)
		for(int t2=t1+1;t2<3;t2++)
			s2=min(s2,max(C[t1][t2],C[t2][t1]));
	return s1+2*s2;
}

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