Lưu ý: Các code mẫu dưới đây chỉ mang tính tham khảo và có thể không AC được bài tập này

Code mẫu của flashmt

const fi='';
      oo=1000000000.00;
var n,k,i,j,cur,re:longint;
    a,b,f:array[1..55555] of real;
    x,yy,t,u,y:real;

function max(x,y:real):real;
begin
     if x>y then max:=x else max:=y;
end;

begin
     assign(input,fi); reset(input);
     read(n,k,y,yy);
     for i:=1 to n do read(a[i],b[i]);
     f[1]:=-oo;
     for i:=2 to n do f[i]:=max(f[i-1],(b[i]-yy)/a[i]);
     cur:=1;
     for i:=1 to k do
     begin
          read(x);
          if x=0 then
          begin
               inc(re); continue;
          end;
          while (cur<n) and (x>a[cur+1]) do inc(cur);
          t:=(b[cur+1]-b[cur])/(a[cur+1]-a[cur]);
          u:=b[cur]-a[cur]*t;
          y:=t*x+u;
          if y-yy>=x*f[cur] then inc(re);
     end;
     writeln(re);
     close(input);
end.

Code mẫu của RR

#include <bits/stdc++.h>

#define FOR(i,a,b) for(int i=(a),_b=(b); i<=_b; i++)
#define FORD(i,a,b) for(int i=(a),_b=(b); i>=_b; i--)
#define REP(i,a) for(int i=0,_a=(a); i<_a; i++)
using namespace std;

struct Point {
    double x, y;

    Point(double x = 0, double y = 0) : x(x), y(y) {}

    Point operator + (Point a) { return Point(x+a.x, y+a.y); }
    Point operator - (Point a) { return Point(x-a.x, y-a.y); }
    Point operator * (double k) { return Point(x*k, y*k); }
} a[50111];

int x[50111], n, k;

int ccw(Point a, Point b, Point c) {
    b = b - a; c = c - a;
    double t = b.x * c.y - b.y * c.x;
    if (fabs(t) < 1e-6) return 0;
    else if (t < 0) return -1;
    else return 1;
}

int main() {
    ios :: sync_with_stdio(false);
    while (cin >> n >> k) {
        int res = 0;
        int y1, y2; cin >> y1 >> y2;
        Point star(0, max(y1, y2));

        FOR(i,1,n) cin >> a[i].x >> a[i].y;
        FOR(i,1,k) cin >> x[i];

        Point mount(0,0);
        int j = 0;
        FOR(i,1,k) { // Process i-th man
            while (j < n && a[j+1].x <= x[i]) {
                ++j;
                if (ccw(a[j], mount, star) == -1) mount = a[j];
            }
            Point P;
            if (fabs(x[i] - a[j].x) < 1e-6) P = a[j];
            else {
                double t = (x[i] - a[j].x) / (a[j+1].x - a[j].x);
                P = Point(x[i], a[j].y + t * (a[j+1].y - a[j].y));
            }
            if (ccw(P, mount, star) != 1) ++res;
        }
        cout << res << endl;
    }
    return 0;
}

Code mẫu của hieult

#include <set>
#include <map>
#include <list>
#include <cmath>
#include <queue>
#include <stack>
#include <cstdio>
#include <string>
#include <vector>
#include <cstdlib>
#include <cstring>
#include <sstream>
#include <iomanip>
#include <iostream>
#include <algorithm>

#include <ctime>
#include <deque>
#include <bitset>
#include <cctype>
#include <utility>
#include <cassert>

using namespace std;

typedef long long ll;
typedef long double ld;
typedef unsigned int ui;
typedef unsigned long long ull;

#define Rep(i,n) for(int i = 0; i < (n); ++i)
#define Repd(i,n) for(int i = (n)-1; i >= 0; --i)
#define For(i,a,b) for(int i = (a); i <= (b); ++i)
#define Ford(i,a,b) for(int i = (a); i >= (b); --i)
#define Fit(i,v) for(__typeof((v).begin()) i = (v).begin(); i != (v).end(); ++i)
#define Fitd(i,v) for(__typeof((v).rbegin()) i = (v).rbegin(); i != (v).rend(); ++i)
#define mp make_pair
#define pb push_back
#define fi first
#define se second
#define sz(a) ((int)(a).size())
#define all(a) (a).begin(), (a).end()
#define ms(a,x) memset(a, x, sizeof(a))

template<class F, class T> T convert(F a, int p = -1) { stringstream ss; if (p >= 0) ss << fixed << setprecision(p); ss << a; T r; ss >> r; return r; }
template<class T> T gcd(T a, T b) { T r; while (b != 0) { r = a % b; a = b; b = r; } return a; }
template<class T> T lcm(T a, T b) { return a / gcd(a, b) * b; }
template<class T> T sqr(T x) { return x * x; }
template<class T> T cube(T x) { return x * x * x; }
template<class T> int getbit(T s, int i) { return (s >> i) & 1; }
template<class T> T onbit(T s, int i) { return s | (T(1) << i); }
template<class T> T offbit(T s, int i) { return s & (~(T(1) << i)); }
template<class T> int cntbit(T s) { return s == 0 ? 0 : cntbit(s >> 1) + (s & 1); }

const int bfsz = 1 << 16;
char bf[bfsz + 5];
int rsz = 0;
int ptr = 0;
char gc() {
    if (rsz <= 0) {
        ptr = 0;
        rsz = (int) fread(bf, 1, bfsz, stdin);
        if (rsz <= 0)
            return EOF;
    }
    --rsz;
    return bf[ptr++];
}
void ga(char &c) {
    c = EOF;
    while (!isalpha(c))
        c = gc();
}
int gs(char s[]) {
    int l = 0;
    char c = gc();
    while (isspace(c))
        c = gc();
    while (c != EOF && !isspace(c)) {
        s[l++] = c;
        c = gc();
    }
    s[l] = '\0';
    return l;
}
template<class T> bool gi(T &v) {
    v = 0;
    char c = gc();
    while (c != EOF && c != '-' && !isdigit(c))
        c = gc();
    if (c == EOF)
        return false;
    bool neg = c == '-';
    if (neg)
        c = gc();
    while (isdigit(c)) {
        v = v * 10 + c - '0';
        c = gc();
    }
    if (neg)
        v = -v;
    return true;
}

typedef pair<int, int> II;

const double PI = acos(-1.0);
const double eps = 1e-9;

const int dr[] = {0, +1, 0, -1};
const int dc[] = {+1, 0, -1, 0};

const int inf = (int)1e9 + 5;
const ll linf = (ll)1e16 + 5;
const ll mod = (ll)1e9 + 7;

#define maxn 100005
int n, k;
ll Yh;
ll x[maxn], y[maxn], X;
ld Y;

pair<ll, ll> lonhon(pair<ll, ll> P0, pair<ll, ll> P1){
    if((P1.se - Yh) * P0.fi - (P0.se - Yh) * P1.fi > 0) return P1;
    return P0;
}

int main(){
//  freopen("in.txt", "r", stdin);

    int res = 0;
    cin >> n >> k;
    cin >> Yh >> Yh;
    For(i, 1, n){
        scanf("%lld %lld", &x[i], &y[i]);
    }

    pair<ll, ll> P;
    int run = 0;
    Rep(rr, k){
        scanf("%lld", &X);
        while(x[run + 1] < X){
            run++;
            P = lonhon(P, mp(x[run], y[run]));
        }

        Y = (X - x[run]) * (ld)(1.0) * (y[run + 1] - y[run]) / (x[run + 1] - x[run]) + y[run];
        if((Y - Yh) * P.fi - (P.se - Yh) * X > -eps) res++;
    }

    cout << res;

    return 0;
}