Submission #708907

#	Time	Username	Problem	Language	Result	Execution time	Memory
708907		Essa2006	Mutating DNA (IOI21_dna)	C++17	100 / 100	70 ms	7364 KiB

dna

#include<bits/stdc++.h>
#include "dna.h"
using namespace std;
#define ll long long 
#define endl '\n'
#define FF first
#define SS second
#define all(a) a.begin(), a.end()
#define mod (ll)(1000000007)
vector<array<array<int, 3>, 3>>AA;
void init(string a, string b) {
    int n=a.size();
    AA.resize(n);
    for(int i=0;i<n;i++){
        if(a[i]=='A')
            a[i]='1';
        if(a[i]=='C')
            a[i]='3';
        if(a[i]=='T')
            a[i]='2';
        if(b[i]=='A')
            b[i]='1';
        if(b[i]=='C')
            b[i]='3';
        if(b[i]=='T')
            b[i]='2';
    }
    for(int i=0;i<n;i++){
        AA[i][a[i]-'1'][b[i]-'1']++;
    }
    for(int i=1;i<n;i++){
        for(int j=0;j<3;j++){
            for(int k=0;k<3;k++){
                AA[i][j][k]+=AA[i-1][j][k];
            }
        }
    }
}

int get_distance(int x, int y) {
    array<array<int, 3>, 3>b;
    for(int j=0;j<3;j++){
        for(int k=0;k<3;k++){
            b[j][k]=AA[y][j][k];
            b[j][k]-=(x?AA[x-1][j][k]:0);
        }
    }
    map<int, int>v, v2;
    for(int i=0;i<3;i++){
        for(int j=i+1;j<3;j++){
            v[i]+=b[i][j], v[j]+=b[j][i], v2[i]+=b[j][i], v2[j]+=b[i][j];
        }
    }
    for(int i=0;i<3;i++){
        if(v[i]!=v2[i]){
            return -1;
        }
    }
    int ans=0, cur=0;
    for(int i=0;i<3;i++){
        for(int j=i+1;j<3;j++){
            int mn=min(b[i][j], b[j][i]);
            ans+=mn;
            b[i][j]-=mn, b[j][i]-=mn;
            cur+=b[i][j]+b[j][i];
        }
    }
    cur/=3;
    cur*=2;
    ans+=cur;
    return ans;
}

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