Submission #436172

#	Time	Username	Problem	Language	Result	Execution time	Memory
436172		cpp219	Ice Hockey World Championship (CEOI15_bobek)	C++14	100 / 100	447 ms	20852 KiB

bobek

#pragma GCC optimization O2
#pragma GCC optimization "unroll-loop"
#pragma target ("avx2")

#include <bits/stdc++.h>
#define ll long long
#define ld long double
#define fs first
#define sc second
using namespace std;
typedef pair<ll,ll> LL;
const ll N = 40 + 9;
const ll inf = 1e9 + 7;
vector<ll> v1,v2;
ll n,k,now,ans,a[N];

void f1(ll i){
    if (i > n/2){
        if (now <= k) v1.push_back(now);
        return;
    }
    f1(i + 1); now += a[i]; f1(i + 1); now -= a[i];
}

void f2(ll i){
    if (i > n){
        if (now <= k) v2.push_back(now);
        return;
    }
    f2(i + 1); now += a[i]; f2(i + 1); now -= a[i];
}

int main(){
    ios_base::sync_with_stdio(NULL); cin.tie(0); cout.tie(0);
    #define task "test"
    if (fopen(task".INP","r")){
        freopen(task".INP","r",stdin);
        //freopen(task".OUT","w",stdout);
    }
    cin>>n>>k;
    for (ll i = 1;i <= n;i++) cin>>a[i];
    f1(1); now = 0; f2(n/2 + 1);
    //for (auto i : v2) cout<<i<<" "; return 0;
    sort(v2.begin(),v2.end());
    for (auto i : v1){
        ll inc = prev(upper_bound(v2.begin(),v2.end(),k - i)) - v2.begin() + 1;
        //cout<<inc<<"x\n";
        ans += inc;
    }
    cout<<ans;
}

Compilation message (stderr)

bobek.cpp:1: warning: ignoring '#pragma GCC optimization' [-Wunknown-pragmas]
    1 | #pragma GCC optimization O2
      | 
bobek.cpp:2: warning: ignoring '#pragma GCC optimization' [-Wunknown-pragmas]
    2 | #pragma GCC optimization "unroll-loop"
      | 
bobek.cpp:3: warning: ignoring '#pragma target ' [-Wunknown-pragmas]
    3 | #pragma target ("avx2")
      | 
bobek.cpp: In function 'int main()':
bobek.cpp:37:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   37 |         freopen(task".INP","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 10 / 10
• Subtask 5: 10 / 10
• Subtask 6: 10 / 10
• Subtask 7: 10 / 10
• Subtask 8: 10 / 10
• Subtask 9: 10 / 10
• Subtask 10: 10 / 10