Submission #638438

#	Time	Username	Problem	Language	Result	Execution time	Memory
638438		abcisosm5	Mutating DNA (IOI21_dna)	C++17	100 / 100	96 ms	23528 KiB

dna

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

int ctoi(char c){
    if(c == 'A') return 0;
    else if(c == 'T') return 1;
    return 2;
}

void init(string a, string b){ //O(N)
    v = vector<vector<vector<int>>>(a.length());
    v[0] = vector<vector<int>>(3, vector<int>(3));
    v[0][ctoi(a[0])][ctoi(b[0])] = 1;
    for(int i = 1; i < a.length(); i++){
        v[i] = v[i-1];
        v[i][ctoi(a[i])][ctoi(b[i])]++;
    }
}

int get_distance(int x, int y){ //O(1)
    //check if possible
    vector<vector<int>> dif = v[y];
    if(x > 0){
        for(int i = 0; i < 3; i++){
            for(int j = 0; j < 3; j++){
                dif[i][j] -= v[x-1][i][j];
            }
        }
    }

    for(int i = 0; i < 3; i++){
        int coli, rowi; coli = rowi = 0;
        for(int j = 0; j < 3; j++){
            coli += dif[i][j];
            rowi += dif[j][i];
        }
        if(coli != rowi) return -1;
    }

    //calculate total # swaps needed
    int mins[3] = {min(dif[0][1], dif[1][0]), min(dif[0][2], dif[2][0]), min(dif[1][2], dif[2][1])};
    int maxs[3] = {max(dif[0][1], dif[1][0]), max(dif[0][2], dif[2][0]), max(dif[1][2], dif[2][1])};
    int oneswap = mins[0] + mins[1] + mins[2];
    int twoswap = (maxs[0]-mins[0]+maxs[1]-mins[1]+maxs[2]-mins[2])*2/3;

    return oneswap + twoswap;
}

Compilation message (stderr)

dna.cpp: In function 'void init(std::string, std::string)':
dna.cpp:15:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   15 |     for(int i = 1; i < a.length(); i++){
      |                    ~~^~~~~~~~~~~~

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