Submission #866180

#	Time	Username	Problem	Language	Result	Execution time	Memory
866180		lomta	Mutating DNA (IOI21_dna)	C++17	100 / 100	34 ms	5400 KiB

dna

#include <bits/stdc++.h>
using namespace std;
 
 
 
const int N = 1e5 + 5;
int pref1[N],pref2[N],pref3[N],pref4[N];
 
 
 
 
 
void init(string a, string b) {
	
	int n=a.size();
	
	pref1[0]=0;
	for(int i=0;i<n;i++){
		pref1[i+1]=pref1[i];
		if(a[i]=='A' && b[i]=='T'){
			pref1[i+1]++;
		}
		if(a[i]=='T' && b[i]=='A'){
			pref1[i+1]--;
		}
	}
	
	pref2[0]=0;
	for(int i=0;i<n;i++){
		pref2[i+1]=pref2[i];
		if(a[i]=='T' && b[i]=='C'){
			pref2[i+1]++;
		}
		if(a[i]=='C' && b[i]=='T'){
			pref2[i+1]--;
		}
	}
	pref3[0]=0;
	for(int i=0;i<n;i++){
		pref3[i+1]=pref3[i];
		if(a[i]=='C' && b[i]=='A'){
			pref3[i+1]++;
		}
		if(a[i]=='A' && b[i]=='C'){
			pref3[i+1]--;
		}
	}
	
	
	
	pref4[0]=0;
	for(int i=0;i<n;i++){
		pref4[i+1]=pref4[i];
		if(a[i]==b[i]){
			pref4[i+1]++;
		}
		
	}
}
 
int get_distance(int x, int y) {
	int sz=y-x+1;
	x++;
	y++;
	x--;
	int a1=pref1[y]-pref1[x];
	int b1=pref2[y]-pref2[x];
	int c1=pref3[y]-pref3[x];
	int d1=pref4[y]-pref4[x];
	/*
	cout<<"a1: "<<a1<<endl;
	cout<<"b1: "<<b1<<endl;
	cout<<"c1: "<<c1<<endl;
	*/
	if(a1==b1 && b1==c1 && c1==a1){
		
		return (sz-abs(a1)-abs(b1)-abs(c1)-abs(d1))/2+(abs(a1)+abs(b1)+abs(c1))/3*2;
	}
	return -1;
}

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