Submission #909803

#	Time	Username	Problem	Language	Result	Execution time	Memory
909803		Marceantasy	Mutating DNA (IOI21_dna)	C++17	100 / 100	34 ms	9868 KiB

dna

#include <bits/stdc++.h>

using namespace std;


int n;
int pref[100000][3][3]; 
int pre1[100000][3], pre2[100000][3]; 
int matrix[3][3];
string letras = "ACT";
void init(string a, string b){
    n = a.size();
    memset(pref, 0, sizeof(pref));
    for (int i = 0; i < n; i++){
        for (int A = 0; A < 3; A++){
            for (int B = 0; B < 3; B++){
                if (i > 0){
                    pref[i][A][B] += pref[i-1][A][B];
                }
                if (a[i] == letras[A] && b[i] == letras[B]){
                    pref[i][A][B]++;
                }
            }
        }
    }
    memset(pre1, 0, sizeof(pre1));
    memset(pre2, 0, sizeof(pre2));
    for (int i = 0; i < n; i++){
        for (int j = 0; j < 3; j++){
            if (i > 0){
                pre1[i][j] = pre1[i-1][j];
                pre2[i][j] = pre2[i-1][j];
            }
            if (a[i] == letras[j]){
                pre1[i][j]++;
            } 
            if (b[i] == letras[j]){
                pre2[i][j]++;
            }
        }
    }



}

int get_distance(int x, int y){
    for(int A  = 0; A < 3; A++){
        if (pre1[y][A] - ( x == 0 ? 0 : pre1[x-1][A]) != pre2[y][A] - ( x == 0 ? 0 : pre2[x-1][A])){
            return -1;
        }
    }
    for (int A = 0; A<3; ++A){
        for(int B = 0; B<3; ++B){
            matrix[A][B] = pref[y][A][B] - ( x == 0 ? 0 : pref[x-1][A][B]);
        }
    }
    int sol = 0;
    for (int A = 0; A<3; ++A){
        for(int B = 0; B<3; ++B){
            if (A == B){
                continue;
            }
            int val = min(matrix[A][B], matrix[B][A]);
            sol += val;
            matrix[A][B] -= val;
            matrix[B][A] -= val;
        }
    }
    int f = 2*max(matrix[0][1], matrix[1][0]);
    return sol + f; 
}

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