Submission #437657

#	Time	Username	Problem	Language	Result	Execution time	Memory
437657		FireGhost1301	Mutating DNA (IOI21_dna)	C++17	100 / 100	54 ms	4896 KiB

dna

/**
    __author__ : FireGhost
    problems_ID: ioi21_dna
*/

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

#define mp make_pair
#define pb push_back
#define eb emplace_back
#define fi first
#define se second
#define all(x) x.begin(), x.end()

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> pii;

const int N = 1e5 + 3;
const int MOD = 1e9 + 7;

int pref_AT[N], pref_TA[N], pref_AC[N], pref_CA[N], pref_TC[N], pref_CT[N];

void init(string a, string b) {
    int n = a.size();
    a = " " + a; b = " " + b;
    for (int i = 1; i <= n; ++i) {
        pref_AT[i] = pref_AT[i - 1] + (a[i] == 'A' && b[i] == 'T');
        pref_TA[i] = pref_TA[i - 1] + (a[i] == 'T' && b[i] == 'A');
        pref_AC[i] = pref_AC[i - 1] + (a[i] == 'A' && b[i] == 'C');
        pref_CA[i] = pref_CA[i - 1] + (a[i] == 'C' && b[i] == 'A');
        pref_TC[i] = pref_TC[i - 1] + (a[i] == 'T' && b[i] == 'C');
        pref_CT[i] = pref_CT[i - 1] + (a[i] == 'C' && b[i] == 'T');
    }
}

int get_distance(int x, int y) {
    ++x, ++y;
    int ans = 0;
    int AT = pref_AT[y] - pref_AT[x - 1];
    int TA = pref_TA[y] - pref_TA[x - 1];
    int AC = pref_AC[y] - pref_AC[x - 1];
    int CA = pref_CA[y] - pref_CA[x - 1];
    int TC = pref_TC[y] - pref_TC[x - 1];
    int CT = pref_CT[y] - pref_CT[x - 1];
    int i = min(AT, TA), j = min(AC, CA), k = min(TC, CT);
    ans += i + j + k;
    AT -= i, TA -= i, AC -= j, CA -= j, TC -= k, CT -= k;
    int A = AT + AC - TA - CA, C = CA + CT - AC - TC, T = TA + TC - AT - CT;
    if (A > 0 || T > 0 || C > 0)
        return -1;
    if (AT == 0) {
        if (TA != AC || AC != CT)
            return -1;
        ans += 2 * TA;
    }
    else {
        if (AT != TC || TC != CA)
            return -1;
        ans += 2 * AT;
    }
    return ans;
}

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