Submission #385627

#	Time	Username	Problem	Language	Result	Execution time	Memory
385627		mihai145	Unscrambling a Messy Bug (IOI16_messy)	C++14	100 / 100	11 ms	512 KiB

messy

#include <vector>
#include <string>
#include <unordered_set>

#include "messy.h"

int N, per[130];

void insertStrings(int st, int dr) {
    if(st == dr) {
        return ;
    }

    int mid = (st + dr) >> 1;

    for(int b = st; b <= mid; b++) {
        std::string s = "";
        for(int j = 1; j <= N; j++) {
            if(j < st) {
                s += '1';
            } else if(j > dr) {
                s += '1';
            } else if(j == b) {
                s += '1';
            } else {
                s += '0';
            }
        }

        add_element(s);
    }

    insertStrings(st, mid);
    insertStrings(mid + 1, dr);
}

void divide(int st, int dr, std::unordered_set<int> emptyPositions, std::unordered_set<int> knownPos) {
    if(st == dr) {
        //std::cout << st << " : " << *emptyPositions.begin() << '\n';
        per[*emptyPositions.begin() - 1] = st - 1;
        return ;
    }

    int mid = (st + dr) >> 1;

    std::unordered_set<int> leftHalf, rightHalf;
    for(int b : emptyPositions) {
        std::string s = "";
        for(int j = 1; j <= N; j++) {
            if(knownPos.find(j) != knownPos.end()) {
                s += '1';
            } else if(j == b) {
                s += '1';
            } else {
                s += '0';
            }
        }

        bool r = check_element(s);

        if(r == true) {
            leftHalf.insert(b);
        }
    }

    for(int b : emptyPositions) {
        if(leftHalf.find(b) == leftHalf.end()) {
            rightHalf.insert(b);
        }
    }

    ///recurse to the left half
    std::unordered_set<int> newEmptyPos, newKnownPos;
    for(int b : emptyPositions) {
        if(rightHalf.find(b) == rightHalf.end()) {
            newEmptyPos.insert(b);
        } else {
            newKnownPos.insert(b);
        }
    }
    for(int b : knownPos) {
        newKnownPos.insert(b);
    }
    divide(st, mid, newEmptyPos, newKnownPos);

    ///recurse to the right half
    newEmptyPos.clear();
    newKnownPos.clear();
    for(int b : emptyPositions) {
        if(leftHalf.find(b) == rightHalf.end()) {
            newEmptyPos.insert(b);
        } else {
            newKnownPos.insert(b);
        }
    }
    for(int b : knownPos) {
        newKnownPos.insert(b);
    }
    divide(mid + 1, dr, newEmptyPos, newKnownPos);
}

std::vector<int> restore_permutation(int n, int w, int r) {
    /*
    add_element("0");
    compile_set();
    check_element("0");
    return std::vector<int>();
    */

    N = n;

    ///Insert all strings
    insertStrings(1, N);

    ///Compile
    compile_set();

    ///Retrieve permutation
    std::unordered_set<int> emptyPositions;
    for(int i = 1; i <= N; i++) {
        emptyPositions.insert(i);
    }
    std::unordered_set<int> knownPos;
    divide(1, N, emptyPositions, knownPos);

    ///Ansert
    std::vector<int> sol(N);
    for(int i = 0; i < N; i++) {
        sol[i] = per[i];
    }
    return sol;
}

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