Submission #966814

#	Time	Username	Problem	Language	Result	Execution time	Memory
966814		YassirSalama	Mutating DNA (IOI21_dna)	C++17	56 / 100	119 ms	34564 KiB

dna

#include <bits/stdc++.h>
#include "dna.h"
using namespace std;
const int dx[4] = {1,0,-1,0}, dy[4] = {0,1,0,-1};
#define endl "\n"
using ull=unsigned long long;
using ll=long long;
using pii=pair<int,int>;
const int mod=1e9+7;
#define OVL(x,s) for(auto y:x) cout<<y<<s; cout<<"\n";
template <typename T> istream& operator>>(istream& is, vector<T> &a) {
    copy_n(istream_iterator<T>(is), a.size(), a.begin()); return is;}
#ifdef IOI
void dbg_out() { cout << endl; } template<typename Head, typename... Tail> void dbg_out(Head H, Tail... T) { cout << ' ' << H; dbg_out(T...); }
#define dbg(...) cout << "(" << #__VA_ARGS__ << "):", dbg_out(__VA_ARGS__);
#else
#define dbg(...) 1337;
#endif
#define pb push_back
#define F first
#define S second
#define all(v) v.begin(),v.end()
const int mxn=1e5+100;
vector<vector<int>> freq1,freq2;
vector<int> eq;
int n;
map<char,int> mp;
vector<vector<vector<int>>> pref;
int sum(int w,int a,int b,vector<vector<int>> &pref){
	if(a==0) return pref[b][w];
	else return pref[b][w]-pref[a-1][w];
}
int sum(int l,int r,vector<int>& pref){
	if(l==0) return pref[r];
	return pref[r]-pref[l-1];
}

void init(string a,string b){
	mp['A']=0;
	mp['T']=1;
	mp['C']=2;
	n=a.length();
	freq1.resize(n+1,vector<int>(3,0));
	freq2.resize(n+1,vector<int>(3,0));
	pref.resize(n+1,vector<vector<int>>(3,vector<int>(3,0)));
	eq.resize(n+1,0);
	for(int i=0;i<n;i++){
		freq1[i][mp[a[i]]]++;
	    freq2[i][mp[b[i]]]++;
	    if(!i) continue;
	    for(int j=0;j<3;j++){
	    	freq1[i][j]+=freq1[i-1][j];
	    	freq2[i][j]+=freq2[i-1][j];
	    }
	}
	for(int i=0;i<n;i++){
	   eq[i]=(a[i]==b[i]);
	   if(i) eq[i]+=eq[i-1];
	}
	for(int i=0;i<n;i++){
	   pref[i][mp[a[i]]][mp[b[i]]]++;
	   if(!i) continue;
		for(int j=0;j<3;j++){
			for(int k=0;k<3;k++){
				pref[i][j][k]+=pref[i-1][j][k];
			}
		}
	}
}
int sum(int a,int b,int l,int r,vector<vector<vector<int>>> &pref){
	if(l==0) return pref[r][a][b];
	else return pref[r][a][b]-pref[l-1][a][b];
}
int get_distance(int x,int y){
    bool ok=true;
    for(int i=0;i<3;i++){
    	ok&=(sum(i,x,y,freq1)==sum(i,x,y,freq2));
    }
    if(!ok) return -1;
    int rest=y-x+1;
    int ans=0;
    rest-=sum(x,y,eq);
    for(int i=0;i<3;i++){
    	for(int j=i+1;j<3;j++){
    		int a=sum(i,j,x,y,pref);
    		int b=sum(j,i,x,y,pref);
    		int c=min(a,b);
    		int k=2*c;
    		ans+=c;
    		rest-=2*c;
    	}
    }

    ans+=max(0,rest-1);
    return ans;
}


#ifdef IOI
signed main(){
	int n,q;
	cin>>n>>q;
	string a;
	cin>>a;
	string b;
	cin>>b;
	init(a,b);
	while(q--){
		int a,b;
		cin>>a>>b;
		int x=get_distance(a,b);
		cout<<x<<endl;
	}
}

#endif

Compilation message (stderr)

dna.cpp: In function 'int get_distance(int, int)':
dna.cpp:88:11: warning: unused variable 'k' [-Wunused-variable]
   88 |       int k=2*c;
      |           ^

• Subtask 1: 21 / 21
• Subtask 2: 22 / 22
• Subtask 3: 13 / 13
• Subtask 4: 0 / 28
• Subtask 5: 0 / 16