Submission #531180

#	Time	Username	Problem	Language	Result	Execution time	Memory
531180		jamezzz	Mutating DNA (IOI21_dna)	C++17	100 / 100	39 ms	7296 KiB

dna

#include "dna.h"

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

int n;
int pfx[100005][6],pa[100005][3],pb[100005][3],cnt[6];

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

void init(string a,string b){
	n=a.length();
	for(int i=1;i<=n;++i){
		for(int j=0;j<3;++j){
			pa[i][j]=pa[i-1][j];
			pb[i][j]=pb[i-1][j];
		}
		++pa[i][to(a[i-1])];
		++pb[i][to(b[i-1])];
	}
	for(int i=0;i<n;++i){
		for(int j=0;j<6;++j){
			pfx[i+1][j]=pfx[i][j];
		}
		int v;
		if(a[i]==b[i])continue;
		if(a[i]=='C'&&b[i]=='A')v=0;
		if(a[i]=='T'&&b[i]=='A')v=1;
		if(a[i]=='A'&&b[i]=='C')v=2;
		if(a[i]=='T'&&b[i]=='C')v=3;
		if(a[i]=='A'&&b[i]=='T')v=4;
		if(a[i]=='C'&&b[i]=='T')v=5;
		++pfx[i+1][v];
	}
}

int get_distance(int x,int y){
	++x;++y;
	bool pos=true;
	for(int i=0;i<3;++i)pos=pos&&(pa[y][i]-pa[x-1][i]==pb[y][i]-pb[x-1][i]);
	if(!pos)return -1;
	for(int i=0;i<6;++i)cnt[i]=pfx[y][i]-pfx[x-1][i];
	int t,ans=0;
	
	t=min(cnt[0],cnt[2]);
	cnt[0]-=t;cnt[2]-=t;ans+=t;
	
	t=min(cnt[1],cnt[4]);
	cnt[1]-=t;cnt[4]-=t;ans+=t;
	
	t=min(cnt[3],cnt[5]);
	cnt[3]-=t;cnt[5]-=t;ans+=t;
	
	ans+=2*(cnt[0]+cnt[2]);
	
	return ans;
}

Compilation message (stderr)

dna.cpp: In function 'void init(std::string, std::string)':
dna.cpp:37:15: warning: 'v' may be used uninitialized in this function [-Wmaybe-uninitialized]
   37 |   ++pfx[i+1][v];
      |     ~~~~~~~~~~^

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