Submission #71611

#	Time	Username	Problem	Language	Result	Execution time	Memory
71611		evpipis	Unscrambling a Messy Bug (IOI16_messy)	C++11	100 / 100	17 ms	572 KiB

messy

//#define TEST

#ifndef TEST
#include "messy.h"
#endif

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

vector<int> restore_permutation(int n, int w, int r);

#ifdef TEST
namespace helper {

    set<string> set_;
    bool compiled = false;
    int n;
    vector<int> p;
    int w;
    int r;

    int read_int() {
        int x;
        cin >> x;
        return x;
    }

}

using namespace helper;


// A convenience function.
int get_p(int i) {
    int ret = p[i];
    return ret;
}

int main() {
    freopen("01", "r", stdin);
    n = read_int();
    w = read_int();
    r = read_int();
    p = vector<int>(n);
    for (int i = 0; i < n; i++) {
        p[i] = read_int();
    }
    vector<int> answer = restore_permutation(n, w, r);

    if (answer.size() != n) {
        printf("WA\n");
        return 0;
    }


    printf("%d", answer[0]);

    for (int i = 1; i < n; i++) {
        printf(" %d", answer[i]);
    }
    printf("\n");
    return 0;
}

void wa() {
    printf("WA\n");
    exit(0);
}

bool check(const string& x) {
    if ((int)x.length() != n) {
        return false;
    }
    for (int i = 0; i < n; i++) {
        if (x[i] != '0' && x[i] != '1') {
            return false;
        }
    }
    return true;
}

void add_element(string x) {
    if (--w < 0 || compiled || !check(x)) {
        wa();
    }
    set_.insert(x);
}

bool check_element(string x) {
    if (--r < 0 || !compiled || !check(x)) {
        wa();
    }
    return set_.count(x);
}

void compile_set() {
    if (compiled) {
        wa();
    }
    compiled = true;
    set<string> compiledSet;
    string compiledElement = string(n, ' ');
    for (set<string>::iterator it = set_.begin(); it != set_.end(); it++) {
        string s = *it;
        for (int i = 0; i < n; i++) {
            compiledElement[i] = s[get_p(i)];
        }
        compiledSet.insert(compiledElement);
    }
    set_ = compiledSet;
}
#endif // TEST

int m;
string str;
vector<int> out;

void add(int l, int r){
    if (l == r) return;

    int mid = (l+r)/2;
    for (int i = l; i <= mid; i++){
        str[i] = '1';
        add_element(str);
        str[i] = '0';
    }

    for (int i = mid+1; i <= r; i++)
        str[i] = '1';
    add(l, mid);
    for (int i = mid+1; i <= r; i++)
        str[i] = '0';

    for (int i = l; i <= mid; i++)
        str[i] = '1';
    add(mid+1, r);
    for (int i = l; i <= mid; i++)
        str[i] = '0';
}

void check(int l, int r){
    if (l == r){
        //cout << str << endl;
        for (int i = 0; i < m; i++)
            if (str[i] == '0')
                out[i] = l;
        return;
    }

    int mid = (l+r)/2;
    vector<int> cnt(m, 0);
    for (int i = 0; i < m; i++){
        if (str[i] == '1') continue;

        cnt[i] = 2;

        str[i] = '1';
        if (check_element(str))
            cnt[i] = 1;
        str[i] = '0';
    }

    for (int i = 0; i < m; i++)
        if (cnt[i] == 2) str[i] = '1';
    check(l, mid);
    for (int i = 0; i < m; i++)
        if (cnt[i] == 2) str[i] = '0';

    for (int i = 0; i < m; i++)
        if (cnt[i] == 1) str[i] = '1';
    check(mid+1, r);
    for (int i = 0; i < m; i++)
        if (cnt[i] == 1) str[i] = '0';
}

vector<int> restore_permutation(int N, int w, int r) {
    m = N;
    str.assign(m, '0');
    out.assign(m, 0);

    add(0, m-1);
    compile_set();
    check(0, m-1);

    return out;
}

• Subtask 1: 20 / 20
• Subtask 2: 18 / 18
• Subtask 3: 11 / 11
• Subtask 4: 21 / 21
• Subtask 5: 30 / 30