Submission #438181

#	Time	Username	Problem	Language	Result	Execution time	Memory
438181		BrunoPloumhans	Mutating DNA (IOI21_dna)	C++17	100 / 100	42 ms	5124 KiB

dna

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

const int MAXN = 100000;

char achars[] = { 'A', 'A', 'T', 'T', 'C', 'C' };
char bchars[] = { 'T', 'C', 'A', 'C', 'A', 'T' };

int sums[MAXN+1][6];

void init(std::string a, std::string b) {
    for (int i = 0; i < a.length(); ++i) {
        for (int j = 0; j < 6; ++j) {
            sums[i+1][j] = sums[i][j] + (a[i] == achars[j] && b[i] == bchars[j]);
        }
    }
}

inline int get(int x, int y, int idx) {
    return sums[y+1][idx] - sums[x][idx];
}

inline void apply_pair(int& p1, int& p2, int& tot) {
    int app = min(p1, p2);
    p1 -= app;
    p2 -= app;
    tot += app;
    //cout << "Paired " << app << endl;
}

inline void apply_triple(int& t1, int& t2, int& t3, int& tot) {
    int app = min(min(t1, t2), t3);
    t1 -= app;
    t2 -= app;
    t3 -= app;
    tot += 2*app;
    //cout << "Tripled " << app << endl;
}

int get_distance(int x, int y) {
    int tot = 0;

    int ab = get(x, y, 0);
    int ac = get(x, y, 1);
    int ba = get(x, y, 2);
    int bc = get(x, y, 3);
    int ca = get(x, y, 4);
    int cb = get(x, y, 5);

    apply_pair(ab, ba, tot);
    apply_pair(ac, ca, tot);
    apply_pair(bc, cb, tot);
    apply_triple(ab, bc, ca, tot);
    apply_triple(ba, ac, cb, tot);

    if (ab == 0 && ac == 0 && ba == 0 && bc == 0 && ca == 0 && cb == 0) {
        return tot;
    } else {
        return -1;
    }
}

Compilation message (stderr)

dna.cpp: In function 'void init(std::string, std::string)':
dna.cpp:13:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   13 |     for (int i = 0; i < a.length(); ++i) {
      |                     ~~^~~~~~~~~~~~

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