Submission #6634627

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Source Code Expand

#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#include <fstream>
#include <iostream>
#include <sstream>
#include <iomanip>
#include <algorithm>
#include <bitset>
#include <array>
#include <vector>
#include <queue>
#include <set>
#include <cmath> // 変数名にy1が使えなくなるかも…。
#include <map>
#include <unordered_map>
#include <unordered_set>
#include <limits>
#include <functional>
#include <string>

typedef __int128_t int128_t;
std::istream &operator>>(std::istream& input, int128_t& value) { // int128_tの入力。入力が64bitに収まる前提。
    long long tmp; input >> tmp; value = tmp;
    return input;
}
std::ostream &operator<<(std::ostream& output, const int128_t value) { // int128_tの出力。出力が64bitに収まる前提。
    output << (long long)value;
    return output;
}

#define rep(i, begin, end) for(int64_t i = (begin); i <= (end); i++)
#define rev(i, begin, end) for(int64_t i = (begin); (end) <= i; i--)

const int MAX_N = 12;
const int MAX_M = MAX_N*MAX_N;
int N, M;
int x[MAX_M], y[MAX_M];
int m[MAX_N][MAX_N] = {};

bool check(std::bitset<MAX_N> bit) {
    rep (i, 0, N - 1) {
        rep (j, i + 1, N - 1) {
            if (bit.test(i) && bit.test(j) && m[i][j] == 0) {
                return false;
            }
        }
    }
    return true;
}

int main(int argc, char **argv){
    std::cin >> N >> M;
    
    rep (i, 1, M) {
        std::cin >> x[i] >> y[i];
        m[x[i] - 1][y[i] - 1] = 1;
    }

    int ret = 0;
    rep (i, 1, (1 << N) - 1) {
        std::bitset<MAX_N> bit(i);
        if (check(bit)) {
            ret = std::max(ret, (int)bit.count());
        }
    }

    std::cout << ret << std::endl;

    return 0;
}

Submission Info

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