Submission #961974

#	Time	Username	Problem	Language	Result	Execution time	Memory
961974		steveonalex	Coins (IOI17_coins)	C++17	100 / 100	12 ms	1940 KiB

coins

#include <bits/stdc++.h>
#include "coins.h"
 
using namespace std;
 
typedef long long ll;
typedef unsigned long long ull;
 
#define ALL(v) (v).begin(), (v).end()
#define MASK(i) (1LL << (i))
#define GETBIT(mask, i) (((mask) >> (i)) & 1)
 
// mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
mt19937_64 rng(1);
ll rngesus(ll l, ll r){return ((ull) rng()) % (r - l + 1) + l;}
 
ll max(ll a, ll b){return (a > b) ? a : b;}
ll min(ll a, ll b){return (a < b) ? a : b;}
 
ll LASTBIT(ll mask){return mask & (-mask);}
ll pop_cnt(ll mask){return __builtin_popcountll(mask);}
ll ctz(ll mask){return __builtin_ctzll(mask);}
ll clz(ll mask){return __builtin_clzll(mask);}
ll logOf(ll mask){return 63 - clz(mask);}
 
template <class T1, class T2>
    bool minimize(T1 &a, T2 b){
        if (a > b){a = b; return true;}
        return false;
    }
template <class T1, class T2>
    bool maximize(T1 &a, T2 b){
        if (a < b){a = b; return true;}
        return false;
    }
template <class T>
    void printArr(T& a, string separator = " ", string finish = "\n"){
        for(auto i: a) cout << i << separator;
        cout << finish;
    }
template <class T>
    void remove_dup(vector<T> &a){
        sort(ALL(a));
        a.resize(unique(ALL(a)) - a.begin());
    }

const int N = 64;

int encode(vector<int> h){
    int ans = 0;
    for(int i = 0; i<N; ++i) if (h[i]) ans ^= i;
    return ans;
}

vector<int> coin_flips(vector<int> b, int c) {
    for(int i = 0; i<N; ++i){
        vector<int> h = b;
        h[i] ^= 1;
        int cur = encode(h);
        if (cur == c) {
            return {i};
        }
    }
}

int find_coin(vector<int> b) {
    return encode(b);
}


// int main(void){
//     ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);

//     vector<int> chess(64, 0);
//     vector<int> mis = coin_flips(chess, 63);
//     printArr(mis);

//     return 0;
// }

Compilation message (stderr)

coins.cpp: In function 'std::vector<int> coin_flips(std::vector<int>, int)':
coins.cpp:64:1: warning: control reaches end of non-void function [-Wreturn-type]
   64 | }
      | ^

• Subtask 1: 10 / 10
• Subtask 2: 15 / 15
• Subtask 3: 10 / 10
• Subtask 4: 15 / 15
• Subtask 5: 50 / 50