Submission #888605

# Submission time Handle Problem Language Result Execution time Memory
888605 2023-12-18T01:21:12 Z ad_red Tri (CEOI09_tri) C++17
100 / 100
505 ms 6484 KB
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define rep(i,a,n) for (ll i=a;i<n;i++)
#define per(i,a,n) for (ll i=n-1;i>=a;i--)
#define pb push_back
#define eb emplace_back
#define mp make_pair
#define all(x) (x).begin(),(x).end()
#define fi first
#define se second
#define SZ(x) ((ll)(x).size())
typedef vector<ll> VI;
typedef basic_string<int> B;
typedef pair<ll,ll> PII;
// head
  
const ll N=100100;
const ll S=1200;
ll n,m;
  
struct pt {
  ll x,y;
  pt(ll _x=0,ll _y=0) : x(_x),y(_y) {}
}p[N];

ll vp(pt a, pt b) {
  return a.x * b.y - b.x * a.y;
}

vector<pt> ch[N];
ll orient(pt a,pt b,pt c) {
  ll v=(b.y-a.y)*1ll*(c.x-b.x)-(b.x-a.x)*1ll*(c.y-b.y);
  return v==0?0:(v<0?-1:1);
}

ll sgn(pt a, pt b, pt c) {
  // -1 if the order is A-B-C from left to right if B is the bottom point
  // 1 or 0 otherwise
  
  ll q = (a.x - b.x) * (c.y - b.y) - (a.y - b.y) * (c.x - b.x);
  return q == 0 ? 0 : (q < 0 ? -1 : 1);
}

bool const operator<(const pt& a,const pt& b) {
  if (orient(pt(0,0),a,b)==0) {
    return (a.x==b.x?a.y<b.y:a.x<b.x);
  }
  return orient(pt(0,0),a,b)>0;
}

bool in_tri(pt a,pt b,pt c,pt p) {
  return orient(a,b,p)!=-1&&orient(b,c,p)!=-1&&orient(c,a,p)!=-1;
}

signed main() {
  scanf("%d%d",&n,&m);
  rep(i,0,n) {
    scanf("%d%d",&p[i].x,&p[i].y);
  }
  sort(p,p+n);
  rep(i,0,n) {
    ch[i/S].pb(p[i]);
  }
  rep(i,0,n) {
    if (ch[i].empty()) continue;
    vector<pt> hull;
    sort(all(ch[i]),[&](pt a,pt b) { return a.x<b.x||(a.x==b.x&&a.y<b.y); });
    for (auto& p:ch[i]) {
      while (SZ(hull)>=2 && sgn(hull[SZ(hull)-2], p, hull[SZ(hull)-1]) <= 0LL) {
        hull.pop_back();
      }
      hull.pb(p);
    }
    ch[i]=hull;
  }
  while (m--) {
    pt a,b;
    scanf("%d%d%d%d",&a.x,&a.y,&b.x,&b.y);
    if (orient(b,pt(0,0),a)<=0) swap(a,b);
    ll L,R;
    {
      L=n-1;
      ll low=0,high=n-1;
      while (low<=high) {
        ll mid=low+high>>1;
        if (orient(p[mid],pt(0,0),a)>=0) {
          L=mid;
          high=mid-1;
        } else {
          low=mid+1;
        }
      }
    }
    {
      R=0;
      ll low=0,high=n-1;
      while (low<=high) {
        ll mid=low+high>>1;
        if (orient(p[mid],pt(0,0),b)<=0) {
          R=mid;
          low=mid+1;
        } else {
          high=mid-1;
        }
      }
    }
    if (L>R) {
      printf("N\n");
      continue;
    }
    if (R-L<=S) {
      bool ok=false;
      rep(i,L,R+1) if (in_tri(a,b,pt(0,0),p[i])) ok=true;
      puts(ok?"Y":"N");
      continue;
    }
    bool ok=false;
    while (L%S!=0) {
      if (in_tri(a,b,pt(0,0),p[L])) ok=true;
      L++;
    }
    while (R>=L&&R%S!=S-1) {
      if (in_tri(a,b,pt(0,0),p[R])) ok=true;
      R--;
    }
    rep(i,L/S,R/S+1) {
      ll sz=SZ(ch[i]);
      ll low=0,high=sz-1;
      while (low<=high) {
        ll mid=low+high>>1;
        if (in_tri(a,b,pt(0,0),ch[i][mid])) {
          ok=true;
          break;
        }
        if (mid+1==sz||(!in_tri(a,b,pt(0,0),ch[i][mid+1])&&orient(ch[i][mid],a,ch[i][mid+1])==1)) {
          high=mid-1;
        } else {
          low=mid+1;
        }
      }
      if (ok) break;
    }
    puts(ok?"Y":"N");
  }
}

Compilation message

tri.cpp: In function 'int main()':
tri.cpp:57:11: warning: format '%d' expects argument of type 'int*', but argument 2 has type 'll*' {aka 'long long int*'} [-Wformat=]
   57 |   scanf("%d%d",&n,&m);
      |          ~^    ~~
      |           |    |
      |           int* ll* {aka long long int*}
      |          %lld
tri.cpp:57:13: warning: format '%d' expects argument of type 'int*', but argument 3 has type 'll*' {aka 'long long int*'} [-Wformat=]
   57 |   scanf("%d%d",&n,&m);
      |            ~^     ~~
      |             |     |
      |             int*  ll* {aka long long int*}
      |            %lld
tri.cpp:59:13: warning: format '%d' expects argument of type 'int*', but argument 2 has type 'll*' {aka 'long long int*'} [-Wformat=]
   59 |     scanf("%d%d",&p[i].x,&p[i].y);
      |            ~^    ~~~~~~~
      |             |    |
      |             int* ll* {aka long long int*}
      |            %lld
tri.cpp:59:15: warning: format '%d' expects argument of type 'int*', but argument 3 has type 'll*' {aka 'long long int*'} [-Wformat=]
   59 |     scanf("%d%d",&p[i].x,&p[i].y);
      |              ~^          ~~~~~~~
      |               |          |
      |               int*       ll* {aka long long int*}
      |              %lld
tri.cpp:79:13: warning: format '%d' expects argument of type 'int*', but argument 2 has type 'll*' {aka 'long long int*'} [-Wformat=]
   79 |     scanf("%d%d%d%d",&a.x,&a.y,&b.x,&b.y);
      |            ~^        ~~~~
      |             |        |
      |             int*     ll* {aka long long int*}
      |            %lld
tri.cpp:79:15: warning: format '%d' expects argument of type 'int*', but argument 3 has type 'll*' {aka 'long long int*'} [-Wformat=]
   79 |     scanf("%d%d%d%d",&a.x,&a.y,&b.x,&b.y);
      |              ~^           ~~~~
      |               |           |
      |               int*        ll* {aka long long int*}
      |              %lld
tri.cpp:79:17: warning: format '%d' expects argument of type 'int*', but argument 4 has type 'll*' {aka 'long long int*'} [-Wformat=]
   79 |     scanf("%d%d%d%d",&a.x,&a.y,&b.x,&b.y);
      |                ~^              ~~~~
      |                 |              |
      |                 int*           ll* {aka long long int*}
      |                %lld
tri.cpp:79:19: warning: format '%d' expects argument of type 'int*', but argument 5 has type 'll*' {aka 'long long int*'} [-Wformat=]
   79 |     scanf("%d%d%d%d",&a.x,&a.y,&b.x,&b.y);
      |                  ~^                 ~~~~
      |                   |                 |
      |                   int*              ll* {aka long long int*}
      |                  %lld
tri.cpp:86:19: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   86 |         ll mid=low+high>>1;
      |                ~~~^~~~~
tri.cpp:99:19: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   99 |         ll mid=low+high>>1;
      |                ~~~^~~~~
tri.cpp:131:19: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  131 |         ll mid=low+high>>1;
      |                ~~~^~~~~
tri.cpp:57:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   57 |   scanf("%d%d",&n,&m);
      |   ~~~~~^~~~~~~~~~~~~~
tri.cpp:59:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   59 |     scanf("%d%d",&p[i].x,&p[i].y);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
tri.cpp:79:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   79 |     scanf("%d%d%d%d",&a.x,&a.y,&b.x,&b.y);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# Verdict Execution time Memory Grader output
1 Correct 4 ms 4184 KB Output is correct
2 Correct 4 ms 4188 KB Output is correct
3 Correct 27 ms 5000 KB Output is correct
4 Correct 218 ms 5376 KB Output is correct
5 Correct 446 ms 6396 KB Output is correct
6 Correct 423 ms 6220 KB Output is correct
7 Correct 505 ms 6484 KB Output is correct
8 Correct 220 ms 6224 KB Output is correct
9 Correct 240 ms 6176 KB Output is correct
10 Correct 268 ms 6484 KB Output is correct