Submission #777345

#	Time	Username	Problem	Language	Result	Execution time	Memory
777345		Trisanu_Das	Mutating DNA (IOI21_dna)	C++17	100 / 100	41 ms	7400 KiB

dna

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

int pref[100005][3][3];
map<char, int> mp;

void init(string a, string b){
    mp['A'] = 0; mp['C'] = 1; mp['T'] = 2;
    for(int i = 1; i <= a.size(); i++) for(int j = 0; j < 3; j++) for(int k = 0; k < 3; k++) pref[i][j][k] = pref[i - 1][j][k] + (mp[a[i - 1]] == j && mp[b[i - 1]] == k);
}

int get_distance(int x, int y){
    int actual = 0, add = 0;
    for(int i = 0; i < 3; i++){
        int j = (i + 1) % 3;
        int m = pref[y + 1][i][j] - pref[x][i][j], n = pref[y + 1][j][i] - pref[x][j][i];
        if(i == 0) add = m - n;
        else if(m - n != add) return -1;
        actual += min(m, n);
    }
    return actual + abs(add) * 2;
}

Compilation message (stderr)

dna.cpp: In function 'void init(std::string, std::string)':
dna.cpp:9:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    9 |     for(int i = 1; i <= a.size(); i++) for(int j = 0; j < 3; j++) for(int k = 0; k < 3; k++) pref[i][j][k] = pref[i - 1][j][k] + (mp[a[i - 1]] == j && mp[b[i - 1]] == k);
      |                    ~~^~~~~~~~~~~

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