Submission #169864

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Source Code Expand

#include <iostream>
#include <vector>
#include <algorithm>
#include <numeric>
#include <set>
#include <map>
#include <string>
#include <stack>
#include <queue>
#include <cmath>
#include <cstdio>
#include <istream>
#include <sstream>
#include <iomanip>
#include <iterator>
#include <climits>
using namespace std;

typedef ostringstream OSS;
typedef istringstream ISS;

typedef vector<int> VI;
typedef vector< VI > VVI;

typedef long long LL;

typedef pair<int, int> PII;
typedef vector<PII> VPII;

#define X first
#define Y second

unsigned long xor128(unsigned long n){ 
    static unsigned long x=time(NULL),y=362436069,z=521288629,w=88675123; 
    unsigned long t; 
    t=(x^(x<<11));
	x=y;
	y=z;
	z=w;
	return w=((w^(w>>19))^(t^(t>>8)))%n;
}

int count_opens(VI &perm, VI &coins) {
	int opens = 0;
	int N = perm.size();

	for (int i = 0; i < N; i++) {
		bool rev = true;
		for (int j = 0; j < i; j++) {
			rev = !(coins[perm[i]] % coins[perm[j]]) ^ rev;
		}
		opens += rev;
	}

	return opens;
}

int main(void) {
	int N;
	cin >> N;
	VI coins(N);
	for(auto &coin : coins) {
		cin >> coin;
	}

	VI perm(N);
	iota(perm.begin(), perm.end(), 0);

	int opens = 0;
	int loop;

	if (N <= 8) {
		loop = 0;
		do {
			opens += count_opens(perm, coins);
			loop++;
		} while(next_permutation(perm.begin(), perm.end()));
	}else {
		loop = 1e+5;
		for (int l = 0; l < loop; l++) {
			random_shuffle(perm.begin(), perm.end(), xor128);
			opens += count_opens(perm, coins);
		}
	}

	cout << ((double)opens / (double)loop) << endl;

	return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:62:12: error: ISO C++ forbids declaration of ‘coin’ with no type [-fpermissive]
./Main.cpp:62:19: error: range-based-for loops are not allowed in C++98 mode
./Main.cpp:67:34: error: ‘iota’ was not declared in this scope