Submission #485376

#	Time	Username	Problem	Language	Result	Execution time	Memory
485376		LptN21	Zvijezda (COCI19_zvijezda)	C++14	110 / 110	151 ms	9520 KiB

zvijezda

#include <bits/stdc++.h>
using namespace std;
#define fastIO ios_base::sync_with_stdio(false), cin.tie(NULL), cout.tie(NULL)
#define PI acos(-1.0)
#define FF first
#define SS second
#define eps 1e-3
// vector
#define pb push_back
#define sz(v) int((v).size())
#define all(v) (v).begin(), (v).end()
#define lb lower_bound
#define ub upper_bound
// bit
#define CNTBIT(x) __builtin_popcount(x)
#define ODDBIT(x) __builtin_parity(x)
#define MASK(i) (1ll<<(i))
#define BIT(x, i) (((x)>>(i))&1)
#define SUBSET(big, small) (((big)&(small))==(small))
#define MINBIT(x) (x)&(-x)
// typedef
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef __int128 i128;
typedef pair<i128, i128> ii;
typedef pair<int, ii> i3;
/* CODE BELOW */
const int N=1e5+7, M=18+1;
const int MOD=1e9+7;
const int oo=1e9+7;

int n, m, k, t;

ii a[N];

/*bool ccw(ii a, ii b, ii c){
	i128 dx1 = b.first - a.first;
	i128 dy1 = b.second - a.second;
	i128 dx2 = c.first - a.first;
	i128 dy2 = c.second - a.second;
	return dx1 * dy2 - dy1 * dx2<0;
}*/

bool ccw(const ii &a,
         const ii &b,
         const ii &c) {
    i128 d1=a.FF*(c.SS-b.SS);
    i128 d2=b.FF*(a.SS-c.SS);
    i128 d3=c.FF*(b.SS-a.SS);
    return d1+d2+d3>0;
}

int BSu(int l, int r, ii p) {
    int mid, ans=l-1;
    while(l<=r) {
        mid=(l+r)/2;
        if(ccw(p, a[mid%n+1], a[mid])) {
            l=mid+1, ans=mid;
        } else r=mid-1;
    }
    return ans;
}
int BSd(int l, int r, ii p) {
    int mid, ans=r+1;
    while(l<=r) {
        mid=(l+r)/2;
        if(ccw(p, a[mid%n+1], a[mid])) {
            r=mid-1, ans=mid;
        } else l=mid+1;
    }
    return ans;
}

bool qry(ii p) {
    bool sl=ccw(p, a[2], a[1]);
    bool sr=ccw(p, a[n/2+2], a[n/2+1]);
    if(sl&&sr) return 1;
    if(sl^sr) {
        if(sl) { // will be of the kind 1 (n) 1 (1) 1 (2) ... 0 (n/2+1) 0 (n/2+2) ...
            int ans=BSu(1, n/2, p);
            int _ans=BSd(n/2+2, n, p);

            return ans+(n-_ans+1)>n/2;
        } else { // // will be of the kind 0 (n) 0 (1) 0 (2) ... 1 (n/2+1) 1 (n/2+2) ...
            int ans=BSd(1, n/2, p);
            int _ans=BSu(n/2+2, n, p);

            return _ans-ans+1>n/2;
        }
    }
    return 0;
}

signed main() {
    //freopen("test.inp", "r", stdin);
    //freopen("test.out", "w", stdout);
    //fastIO;
    scanf("%d%d", &t, &n);
    ll x, y;
    for(int i=1;i<=n;i++) {
        scanf("%lld%lld", &x, &y);
        a[i]=ii(x, y);
    }

    #define sqr3(x) 1LL*(x)*(x)*(x)
    scanf("%d", &m);
    ll cntAns=0;
    for(int i=1;i<=m;i++) {
        ii p; scanf("%lld%lld", &x, &y);
        p.FF = x ^ (t * sqr3(cntAns));
        p.SS = y ^ (t * sqr3(cntAns));

        bool ans=qry(p); cntAns+=ans;
        if(ans) printf("DA");
        else printf("NE");
        printf("\n");
    }

    return 0;
}
/* stuff you should look for
    - int overflow, array bounds
    - special/edge cases (n=1?)
    - do smth instead of nothing and stay organized
    - WRITE STUFF DOWN
    - DONT JUST STICK ON ONE APPROACH
*/

Compilation message (stderr)

zvijezda.cpp: In function 'int main()':
zvijezda.cpp:99:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   99 |     scanf("%d%d", &t, &n);
      |     ~~~~~^~~~~~~~~~~~~~~~
zvijezda.cpp:102:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  102 |         scanf("%lld%lld", &x, &y);
      |         ~~~~~^~~~~~~~~~~~~~~~~~~~
zvijezda.cpp:107:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  107 |     scanf("%d", &m);
      |     ~~~~~^~~~~~~~~~
zvijezda.cpp:110:20: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  110 |         ii p; scanf("%lld%lld", &x, &y);
      |               ~~~~~^~~~~~~~~~~~~~~~~~~~

• Subtask 1: 20 / 20
• Subtask 2: 30 / 30
• Subtask 3: 60 / 60